<?xml version="1.0" encoding="US-ASCII"?>
<!-- Generated by CompSci Transform (tm) - http://www.compsciresources.com -->
<!-- Created: Fri Jul 02 14:10:59 UTC 2021 -->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_ConsolidatedBalanceSheet" roleURI="http://www.bctg.com/role/ConsolidatedBalanceSheet"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_ConsolidatedBalanceSheet_Parentheticals" roleURI="http://www.bctg.com/role/ConsolidatedBalanceSheet_Parentheticals"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_ConsolidatedIncomeStatement" roleURI="http://www.bctg.com/role/ConsolidatedIncomeStatement"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_ShareholdersEquityType2or3" roleURI="http://www.bctg.com/role/ShareholdersEquityType2or3"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_ConsolidatedCashFlow" roleURI="http://www.bctg.com/role/ConsolidatedCashFlow"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_DescriptionofOrganizationandBusinessOperations" roleURI="http://www.bctg.com/role/DescriptionofOrganizationandBusinessOperations"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_SummaryofSignificantAccountingPolicies" roleURI="http://www.bctg.com/role/SummaryofSignificantAccountingPolicies"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_InitialPublicOffering" roleURI="http://www.bctg.com/role/InitialPublicOffering"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_RelatedPartyTransactions" roleURI="http://www.bctg.com/role/RelatedPartyTransactions"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_CommitmentsandContingencies" roleURI="http://www.bctg.com/role/CommitmentsandContingencies"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_StockholdersEquity" roleURI="http://www.bctg.com/role/StockholdersEquity"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_FairValueMeasurements" roleURI="http://www.bctg.com/role/FairValueMeasurements"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_SubsequentEvents" roleURI="http://www.bctg.com/role/SubsequentEvents"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_PrivatePlacement" roleURI="http://www.bctg.com/role/PrivatePlacement"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_IncomeTaxes" roleURI="http://www.bctg.com/role/IncomeTaxes"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_AccountingPoliciesByPolicy" roleURI="http://www.bctg.com/role/AccountingPoliciesByPolicy"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_FairValueMeasurementsTables" roleURI="http://www.bctg.com/role/FairValueMeasurementsTables"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_IncomeTaxesTables" roleURI="http://www.bctg.com/role/IncomeTaxesTables"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_ScheduleofmeasuredatfairvalueonarecurringbasisTable" roleURI="http://www.bctg.com/role/ScheduleofmeasuredatfairvalueonarecurringbasisTable"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_ScheduleofmeasuredatfairvalueonarecurringbasisTable0" roleURI="http://www.bctg.com/role/ScheduleofmeasuredatfairvalueonarecurringbasisTable0"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_ScheduleofincometaxprovisionbenefitTable" roleURI="http://www.bctg.com/role/ScheduleofincometaxprovisionbenefitTable"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_ScheduleofnetdeferredtaxassetsTable" roleURI="http://www.bctg.com/role/ScheduleofnetdeferredtaxassetsTable"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_ScheduleofstatutoryfederalincometaxratebenefitTable" roleURI="http://www.bctg.com/role/ScheduleofstatutoryfederalincometaxratebenefitTable"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_DescriptionofOrganizationandBusinessOperationsDetails" roleURI="http://www.bctg.com/role/DescriptionofOrganizationandBusinessOperationsDetails"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_SummaryofSignificantAccountingPoliciesDetails" roleURI="http://www.bctg.com/role/SummaryofSignificantAccountingPoliciesDetails"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_InitialPublicOfferingDetails" roleURI="http://www.bctg.com/role/InitialPublicOfferingDetails"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_RelatedPartyTransactionsDetails" roleURI="http://www.bctg.com/role/RelatedPartyTransactionsDetails"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_CommitmentsandContingenciesDetails" roleURI="http://www.bctg.com/role/CommitmentsandContingenciesDetails"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_StockholdersEquityDetails" roleURI="http://www.bctg.com/role/StockholdersEquityDetails"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_FairValueMeasurementsDetails" roleURI="http://www.bctg.com/role/FairValueMeasurementsDetails"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_PrivatePlacementDetails" roleURI="http://www.bctg.com/role/PrivatePlacementDetails"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#bctg_r_IncomeTaxesDetails" roleURI="http://www.bctg.com/role/IncomeTaxesDetails"/>
  <roleRef xlink:type="simple" xlink:href="bctg-20210331.xsd#DocumentAndEntityInformation" roleURI="http://www.bctg.com/role/DocumentAndEntityInformation"/>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/ConsolidatedBalanceSheet">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrentAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AssetsCurrentAbstract" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PrepaidExpenseCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrepaidExpenseCurrent"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_PrepaidExpenseCurrent" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrent"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrent" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsHeldInTrustNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsHeldInTrustNoncurrent"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsHeldInTrustNoncurrent" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Assets" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Assets"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_Assets" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_LiabilitiesCurrentAbstract" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccountsPayableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsPayableCurrent"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccountsPayableCurrent" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccruedLiabilitiesCurrent" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccruedIncomeTaxes" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccruedIncomeTaxes"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccruedIncomeTaxes" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="FranchiseTaxPayables" xlink:href="bctg-20210331.xsd#bctg_FranchiseTaxPayables"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="FranchiseTaxPayables" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesCurrent"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_LiabilitiesCurrent" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="DeferredUnderwritingCommissions" xlink:href="bctg-20210331.xsd#bctg_DeferredUnderwritingCommissions"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="DeferredUnderwritingCommissions" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Liabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Liabilities"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_Liabilities" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommitmentsAndContingencies"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_CommitmentsAndContingencies" order="7.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_TemporaryEquityCarryingAmountAttributableToParent" order="8.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StockholdersEquityAbstract" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockValue"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_PreferredStockValue" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockValue"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_CommonStockValue" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_AdditionalPaidInCapitalCommonStock" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquity" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/ConsolidatedBalanceSheet_Parentheticals">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
    <loc xlink:type="locator" xlink:label="SubjectToPossibleRedemptionPerSharesRedemptionValue" xlink:href="bctg-20210331.xsd#bctg_SubjectToPossibleRedemptionPerSharesRedemptionValue"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="SubjectToPossibleRedemptionPerSharesRedemptionValue" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="CommonStockSubjectToPossibleRedemptionShares" xlink:href="bctg-20210331.xsd#bctg_CommonStockSubjectToPossibleRedemptionShares"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="CommonStockSubjectToPossibleRedemptionShares" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesAuthorized" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesIssued"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesIssued" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesOutstanding" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesAuthorized" order="7.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesIssued"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesIssued" order="8.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesOutstanding" order="9.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/ConsolidatedIncomeStatement">
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GeneralAndAdministrativeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_GeneralAndAdministrativeExpense" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionSellingGeneralAndAdministrativeExpensesFromTransactionsWithRelatedParty" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionSellingGeneralAndAdministrativeExpensesFromTransactionsWithRelatedParty"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_RelatedPartyTransactionSellingGeneralAndAdministrativeExpensesFromTransactionsWithRelatedParty" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProductionTaxExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProductionTaxExpense"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_ProductionTaxExpense" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingIncomeLoss"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ProductionTaxExpense" xlink:to="us-gaap_OperatingIncomeLoss" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestIncomeOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeOther"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestIncomeOther" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_IncomeTaxExpenseBenefit" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_NetIncomeLoss" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_EarningsPerShareBasicAndDiluted" order="7.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="WeightedAverageSharesOutstandingOfFounderSharesinShares" xlink:href="bctg-20210331.xsd#bctg_WeightedAverageSharesOutstandingOfFounderSharesinShares"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="WeightedAverageSharesOutstandingOfFounderSharesinShares" order="8.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="BasicAndDilutedNetLossPerShareFounderSharesi" xlink:href="bctg-20210331.xsd#bctg_BasicAndDilutedNetLossPerShareFounderSharesi"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="BasicAndDilutedNetLossPerShareFounderSharesi" order="9.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/ShareholdersEquityType2or3">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementTable"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementTable" order="1.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementEquityComponentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_CommonStockMember" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdditionalPaidInCapitalMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_AdditionalPaidInCapitalMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetainedEarningsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_RetainedEarningsMember" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="3.0"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="2.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquity" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesOutstanding"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SharesOutstanding" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueOther"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueOther" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesOther"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesOther" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedOwnshareLendingArrangementIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedOwnshareLendingArrangementIssuanceCosts"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedOwnshareLendingArrangementIssuanceCosts" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="SaleOfPrivatePlacementSharesToSponsorInPrivatePlacement" xlink:href="bctg-20210331.xsd#bctg_SaleOfPrivatePlacementSharesToSponsorInPrivatePlacement"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="SaleOfPrivatePlacementSharesToSponsorInPrivatePlacement" order="7.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="SaleOfPrivatePlacementSharesToSponsorInPrivatePlacementinShares" xlink:href="bctg-20210331.xsd#bctg_SaleOfPrivatePlacementSharesToSponsorInPrivatePlacementinShares"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="SaleOfPrivatePlacementSharesToSponsorInPrivatePlacementinShares" order="8.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockRedeemedOrCalledDuringPeriodValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockRedeemedOrCalledDuringPeriodValue"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockRedeemedOrCalledDuringPeriodValue" order="9.0" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockRedeemedOrCalledDuringPeriodShares" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockRedeemedOrCalledDuringPeriodShares"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockRedeemedOrCalledDuringPeriodShares" order="10.0" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
    <loc xlink:type="locator" xlink:label="CommonStockSubjectToPossiblseRedemption" xlink:href="bctg-20210331.xsd#bctg_CommonStockSubjectToPossiblseRedemption"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="CommonStockSubjectToPossiblseRedemption" order="11.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="CommonStockSubjectToPossibleRedemptionShare" xlink:href="bctg-20210331.xsd#bctg_CommonStockSubjectToPossibleRedemptionShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="CommonStockSubjectToPossibleRedemptionShare" order="12.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLoss" order="13.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquity_0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquity_0" order="14.0" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharesOutstanding_0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesOutstanding"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SharesOutstanding_0" order="15.0" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/ConsolidatedCashFlow">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfCashFlowsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetIncomeLoss" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentIncomeInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InvestmentIncomeInterest"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_InvestmentIncomeInterest" order="1.0" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidExpense"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInPrepaidExpense" order="0.0" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccruedTaxesPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedTaxesPayable"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccruedTaxesPayable" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FranchisorCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FranchisorCosts"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_FranchisorCosts" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="ProceedsFromCashDepositedInTrustAccount" xlink:href="bctg-20210331.xsd#bctg_ProceedsFromCashDepositedInTrustAccount"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="ProceedsFromCashDepositedInTrustAccount" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ProceedsFromCashDepositedInTrustAccount" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromRelatedPartyDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromRelatedPartyDebt"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromRelatedPartyDebt" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromRepaymentsOfRelatedPartyDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromRepaymentsOfRelatedPartyDebt"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromRepaymentsOfRelatedPartyDebt" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_PaymentsOfStockIssuanceCosts" order="5.0" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PaymentsOfStockIssuanceCosts" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_0" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="OfferingCostsIncludedInNotePayableRelatedParty" xlink:href="bctg-20210331.xsd#bctg_OfferingCostsIncludedInNotePayableRelatedParty"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="OfferingCostsIncludedInNotePayableRelatedParty" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="OfferingCostsIncludedInAccruedExpenses" xlink:href="bctg-20210331.xsd#bctg_OfferingCostsIncludedInAccruedExpenses"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="OfferingCostsIncludedInAccruedExpenses" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="DeferredUnderwritingCommission" xlink:href="bctg-20210331.xsd#bctg_DeferredUnderwritingCommission"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="DeferredUnderwritingCommission" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="InitialValueOfCommonStockSubjectToPossibleRedemption" xlink:href="bctg-20210331.xsd#bctg_InitialValueOfCommonStockSubjectToPossibleRedemption"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="InitialValueOfCommonStockSubjectToPossibleRedemption" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="ChangeInValueOfCommonStockSubjectToPossibleRedemptions" xlink:href="bctg-20210331.xsd#bctg_ChangeInValueOfCommonStockSubjectToPossibleRedemptions"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="ChangeInValueOfCommonStockSubjectToPossibleRedemptions" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/DescriptionofOrganizationandBusinessOperations">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/SummaryofSignificantAccountingPolicies">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_SignificantAccountingPoliciesTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/InitialPublicOffering">
    <loc xlink:type="locator" xlink:label="ProposedOfferingDisclosureAbstract" xlink:href="bctg-20210331.xsd#bctg_ProposedOfferingDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="ProposedOfferingDisclosureTextBlock" xlink:href="bctg-20210331.xsd#bctg_ProposedOfferingDisclosureTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ProposedOfferingDisclosureAbstract" xlink:to="ProposedOfferingDisclosureTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/RelatedPartyTransactions">
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionsDisclosureTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionsAbstract" xlink:to="us-gaap_RelatedPartyTransactionsDisclosureTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/CommitmentsandContingencies">
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/StockholdersEquity">
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityNoteAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityNoteAbstract" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/FairValueMeasurements">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueDisclosuresAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueDisclosuresTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueDisclosuresTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/SubsequentEvents">
    <loc xlink:type="locator" xlink:label="us-gaap_SubsequentEventsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsequentEventsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsequentEventsTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventsAbstract" xlink:to="us-gaap_SubsequentEventsTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/PrivatePlacement">
    <loc xlink:type="locator" xlink:label="PrivatePlacementDisclosureAbstract" xlink:href="bctg-20210331.xsd#bctg_PrivatePlacementDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="PrivatePlacementTable" xlink:href="bctg-20210331.xsd#bctg_PrivatePlacementTable"/>
    <loc xlink:type="locator" xlink:label="PrivatePlacementLineItems" xlink:href="bctg-20210331.xsd#bctg_PrivatePlacementLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="PrivatePlacementDisclosureAbstract" xlink:to="PrivatePlacementTable" order="1.0"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="PrivatePlacementTable" xlink:to="PrivatePlacementLineItems" order="1.0"/>
    <loc xlink:type="locator" xlink:label="PrivatePlacementDisclosureTextBlock" xlink:href="bctg-20210331.xsd#bctg_PrivatePlacementDisclosureTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="PrivatePlacementLineItems" xlink:to="PrivatePlacementDisclosureTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/IncomeTaxes">
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/AccountingPoliciesByPolicy">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="EmergingGrowthCompanyPolicyTextBlock" xlink:href="bctg-20210331.xsd#bctg_EmergingGrowthCompanyPolicyTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="EmergingGrowthCompanyPolicyTextBlock" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConcentrationRiskCreditRisk" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskCreditRisk"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ConcentrationRiskCreditRisk" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsPolicyTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_CashAndCashEquivalentsPolicyTextBlock" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InvestmentPolicyTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_InvestmentPolicyTextBlock" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UseOfEstimates" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UseOfEstimates"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_UseOfEstimates" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueOfFinancialInstrumentsPolicy"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_FairValueOfFinancialInstrumentsPolicy" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_FairValueMeasurementPolicyPolicyTextBlock" order="7.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredChargesPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredChargesPolicyTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_DeferredChargesPolicyTextBlock" order="8.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharesSubjectToMandatoryRedemptionChangesInRedemptionValuePolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesSubjectToMandatoryRedemptionChangesInRedemptionValuePolicyTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_SharesSubjectToMandatoryRedemptionChangesInRedemptionValuePolicyTextBlock" order="9.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_IncomeTaxPolicyTextBlock" order="10.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerSharePolicyTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_EarningsPerSharePolicyTextBlock" order="11.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" order="12.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/FairValueMeasurementsTables">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueDisclosuresAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/IncomeTaxesTables">
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/ScheduleofmeasuredatfairvalueonarecurringbasisTable">
    <loc xlink:type="locator" xlink:label="ScheduleOfMeasuredAtFairValueOnARecurringBasisAbstract" xlink:href="bctg-20210331.xsd#bctg_ScheduleOfMeasuredAtFairValueOnARecurringBasisAbstract"/>
    <loc xlink:type="locator" xlink:label="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable" xlink:href="bctg-20210331.xsd#bctg_FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable"/>
    <loc xlink:type="locator" xlink:label="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisLineItems" xlink:href="bctg-20210331.xsd#bctg_FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ScheduleOfMeasuredAtFairValueOnARecurringBasisAbstract" xlink:to="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable" order="1.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel1Member" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueInputsLevel1Member" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel2Member" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueInputsLevel2Member" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueInputsLevel3Member" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable" xlink:to="us-gaap_CashAndCashEquivalentsAxis" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_USTreasurySecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="us-gaap_USTreasurySecuritiesMember" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="USTreasurySecuritiesMaturingMarch42021Member" xlink:href="bctg-20210331.xsd#bctg_USTreasurySecuritiesMaturingMarch42021Member"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="USTreasurySecuritiesMaturingMarch42021Member" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable" xlink:to="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisLineItems" order="3.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsHeldInTrust" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsHeldInTrust"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisLineItems" xlink:to="us-gaap_AssetsHeldInTrust" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/ScheduleofmeasuredatfairvalueonarecurringbasisTable0">
    <loc xlink:type="locator" xlink:label="ScheduleOfMeasuredAtFairValueOnARecurringBasisAbstract" xlink:href="bctg-20210331.xsd#bctg_ScheduleOfMeasuredAtFairValueOnARecurringBasisAbstract"/>
    <loc xlink:type="locator" xlink:label="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable" xlink:href="bctg-20210331.xsd#bctg_FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable"/>
    <loc xlink:type="locator" xlink:label="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisLineItems" xlink:href="bctg-20210331.xsd#bctg_FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ScheduleOfMeasuredAtFairValueOnARecurringBasisAbstract" xlink:to="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable" order="1.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel1Member" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
<!-- [WMV5][XcpuxYn59dz7vgYynUDuwG7r97K2jUTysl7vcz0lJt/tSeJz73kx1cLt0ZFF2SK/vxBCY0vdSrYXuQBXaND6vbMnUEYKy6S8HgcraHjAeyuAdEjis4ljHG+cAm8tXbGb26uu2b9QZeatysMaj5Pr78eagdpV2wMIsmCKi4co6QhGRZ6FdlIJYPxeGNNqfnH57F/4yiM9xLYkK6FCnjj6+5fU1ArECIpnpm7hlw65dJy0d+9YGYyI26cNzLZy3Wej0MD+x7l/GEnNy6UAkCZB7SoIhA0egO35] CSR-->
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueInputsLevel1Member" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel2Member" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueInputsLevel2Member" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueInputsLevel3Member" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable" xlink:to="us-gaap_CashAndCashEquivalentsAxis" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" order="0.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_USTreasurySecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="us-gaap_USTreasurySecuritiesMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MoneyMarketFundsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MoneyMarketFundsMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="us-gaap_MoneyMarketFundsMember" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisTable" xlink:to="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisLineItems" order="3.0"/>
    <loc xlink:type="locator" xlink:label="DescriptionAbstract" xlink:href="bctg-20210331.xsd#bctg_DescriptionAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="FairValueMeasurementsDetailsScheduleofmeasuredatfairvalueonarecurringbasisLineItems" xlink:to="DescriptionAbstract" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsHeldInTrustAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsHeldInTrustAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionAbstract" xlink:to="us-gaap_AssetsHeldInTrustAbstract" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsHeldInTrust" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsHeldInTrust"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsHeldInTrustAbstract" xlink:to="us-gaap_AssetsHeldInTrust" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/ScheduleofincometaxprovisionbenefitTable">
    <loc xlink:type="locator" xlink:label="ScheduleOfIncomeTaxProvisionBenefitAbstract" xlink:href="bctg-20210331.xsd#bctg_ScheduleOfIncomeTaxProvisionBenefitAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ScheduleOfIncomeTaxProvisionBenefitAbstract" xlink:to="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" xlink:to="us-gaap_CurrentFederalTaxExpenseBenefit" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" xlink:to="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredIncomeTaxesAndTaxCreditsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxesAndTaxCreditsAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ScheduleOfIncomeTaxProvisionBenefitAbstract" xlink:to="us-gaap_DeferredIncomeTaxesAndTaxCreditsAbstract" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredIncomeTaxesAndTaxCreditsAbstract" xlink:to="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredIncomeTaxesAndTaxCreditsAbstract" xlink:to="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="ValuationAllowance" xlink:href="bctg-20210331.xsd#bctg_ValuationAllowance"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ScheduleOfIncomeTaxProvisionBenefitAbstract" xlink:to="ValuationAllowance" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ScheduleOfIncomeTaxProvisionBenefitAbstract" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/ScheduleofnetdeferredtaxassetsTable">
    <loc xlink:type="locator" xlink:label="ScheduleOfNetDeferredTaxAssetsAbstract" xlink:href="bctg-20210331.xsd#bctg_ScheduleOfNetDeferredTaxAssetsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ScheduleOfNetDeferredTaxAssetsAbstract" xlink:to="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsGross" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsGross"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxAssetsGross" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxAssetsValuationAllowance" order="2.0" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsNet"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxAssetsNet" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/ScheduleofstatutoryfederalincometaxratebenefitTable">
    <loc xlink:type="locator" xlink:label="ScheduleOfStatutoryFederalIncomeTaxRateBenefitAbstract" xlink:href="bctg-20210331.xsd#bctg_ScheduleOfStatutoryFederalIncomeTaxRateBenefitAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ScheduleOfStatutoryFederalIncomeTaxRateBenefitAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ScheduleOfStatutoryFederalIncomeTaxRateBenefitAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ScheduleOfStatutoryFederalIncomeTaxRateBenefitAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/DescriptionofOrganizationandBusinessOperationsDetails">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <loc xlink:type="locator" xlink:label="DescriptionofOrganizationandBusinessOperationsDetailsTable" xlink:href="bctg-20210331.xsd#bctg_DescriptionofOrganizationandBusinessOperationsDetailsTable"/>
    <loc xlink:type="locator" xlink:label="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:href="bctg-20210331.xsd#bctg_DescriptionofOrganizationandBusinessOperationsDetailsLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="DescriptionofOrganizationandBusinessOperationsDetailsTable" order="1.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementClassOfStockAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_CommonStockMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsidiarySaleOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IPOMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IPOMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_IPOMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="PublicSharesMember" xlink:href="bctg-20210331.xsd#bctg_PublicSharesMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="PublicSharesMember" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PrivatePlacementMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrivatePlacementMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_PrivatePlacementMember" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="TypeOfAgreementAxis" xlink:href="bctg-20210331.xsd#bctg_TypeOfAgreementAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsTable" xlink:to="TypeOfAgreementAxis" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="TypeOfAgreementDomain" xlink:href="bctg-20210331.xsd#bctg_TypeOfAgreementDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="TypeOfAgreementAxis" xlink:to="TypeOfAgreementDomain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="MergerAgreementMember" xlink:href="bctg-20210331.xsd#bctg_MergerAgreementMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="TypeOfAgreementAxis" xlink:to="MergerAgreementMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsTable" xlink:to="us-gaap_BusinessAcquisitionAxis" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="BusinessCombinationMember" xlink:href="bctg-20210331.xsd#bctg_BusinessCombinationMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="BusinessCombinationMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsTable" xlink:to="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" order="5.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesOther"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesOther" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockPricePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="us-gaap_SaleOfStockPricePerShare" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="OfferingCost" xlink:href="bctg-20210331.xsd#bctg_OfferingCost"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="OfferingCost" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AmortizationOfDeferredSalesCommissions" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfDeferredSalesCommissions"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="us-gaap_AmortizationOfDeferredSalesCommissions" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="BusinessCombinationFairMarketValuePercentage" xlink:href="bctg-20210331.xsd#bctg_BusinessCombinationFairMarketValuePercentage"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="BusinessCombinationFairMarketValuePercentage" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="PercentageOfFairMarketValue" xlink:href="bctg-20210331.xsd#bctg_PercentageOfFairMarketValue"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="PercentageOfFairMarketValue" order="7.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="NetTangibleAssets" xlink:href="bctg-20210331.xsd#bctg_NetTangibleAssets"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="NetTangibleAssets" order="8.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="PublicPerSharePrice" xlink:href="bctg-20210331.xsd#bctg_PublicPerSharePrice"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="PublicPerSharePrice" order="9.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RestrictedInvestmentsPercentOfNetAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedInvestmentsPercentOfNetAssets"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="us-gaap_RestrictedInvestmentsPercentOfNetAssets" order="10.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireePercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireePercentage"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireePercentage" order="11.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="PercentageOfOutstandingPublicShares" xlink:href="bctg-20210331.xsd#bctg_PercentageOfOutstandingPublicShares"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="PercentageOfOutstandingPublicShares" order="12.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="PricePerShare" xlink:href="bctg-20210331.xsd#bctg_PricePerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="PricePerShare" order="13.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="TrustAccountPublicShare" xlink:href="bctg-20210331.xsd#bctg_TrustAccountPublicShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="TrustAccountPublicShare" order="14.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" order="15.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="ClosingProceeds" xlink:href="bctg-20210331.xsd#bctg_ClosingProceeds"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="ClosingProceeds" order="16.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="SubscriptionAgreementDescription" xlink:href="bctg-20210331.xsd#bctg_SubscriptionAgreementDescription"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="SubscriptionAgreementDescription" order="17.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Cash" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Cash"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="us-gaap_Cash" order="18.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="WorkingCapitalDeficit" xlink:href="bctg-20210331.xsd#bctg_WorkingCapitalDeficit"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="WorkingCapitalDeficit" order="19.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="LiquidityAndCapitalResourcesDescription" xlink:href="bctg-20210331.xsd#bctg_LiquidityAndCapitalResourcesDescription"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="LiquidityAndCapitalResourcesDescription" order="20.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="PaymentOnNotesPayable" xlink:href="bctg-20210331.xsd#bctg_PaymentOnNotesPayable"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="PaymentOnNotesPayable" order="21.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="LoanAmountValue" xlink:href="bctg-20210331.xsd#bctg_LoanAmountValue"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DescriptionofOrganizationandBusinessOperationsDetailsLineItems" xlink:to="LoanAmountValue" order="22.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/SummaryofSignificantAccountingPoliciesDetails">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <loc xlink:type="locator" xlink:label="SummaryofSignificantAccountingPoliciesDetailsTable" xlink:href="bctg-20210331.xsd#bctg_SummaryofSignificantAccountingPoliciesDetailsTable"/>
    <loc xlink:type="locator" xlink:label="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:href="bctg-20210331.xsd#bctg_SummaryofSignificantAccountingPoliciesDetailsLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="SummaryofSignificantAccountingPoliciesDetailsTable" order="1.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementEquityComponentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_CommonStockMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsTable" xlink:to="SummaryofSignificantAccountingPoliciesDetailsLineItems" order="2.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashFDICInsuredAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashFDICInsuredAmount"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_CashFDICInsuredAmount" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="CommonStockSubjectToPossibleRedemptions" xlink:href="bctg-20210331.xsd#bctg_CommonStockSubjectToPossibleRedemptions"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="CommonStockSubjectToPossibleRedemptions" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="CommonStockSubjectToPossibleRedemption" xlink:href="bctg-20210331.xsd#bctg_CommonStockSubjectToPossibleRedemption"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="CommonStockSubjectToPossibleRedemption" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="InvestmentIncomeOnTrustAccount" xlink:href="bctg-20210331.xsd#bctg_InvestmentIncomeOnTrustAccount"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="InvestmentIncomeOnTrustAccount" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="NetOfApplicableIncomeAndFranchiseTaxes" xlink:href="bctg-20210331.xsd#bctg_NetOfApplicableIncomeAndFranchiseTaxes"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="NetOfApplicableIncomeAndFranchiseTaxes" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareNonrecurringCommonControlIntraEntityTransactionsDescription" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareNonrecurringCommonControlIntraEntityTransactionsDescription"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_EarningsPerShareNonrecurringCommonControlIntraEntityTransactionsDescription" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TemporaryEquityShareSubscriptions" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityShareSubscriptions"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_TemporaryEquityShareSubscriptions" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesIssued"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_SharesIssued" order="7.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="FranchiseTaxes" xlink:href="bctg-20210331.xsd#bctg_FranchiseTaxes"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="FranchiseTaxes" order="8.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProfitLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProfitLoss"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="SummaryofSignificantAccountingPoliciesDetailsLineItems" xlink:to="us-gaap_ProfitLoss" order="9.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/InitialPublicOfferingDetails">
    <loc xlink:type="locator" xlink:label="ProposedOfferingDisclosureAbstract" xlink:href="bctg-20210331.xsd#bctg_ProposedOfferingDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="InitialPublicOfferingDetailsTable" xlink:href="bctg-20210331.xsd#bctg_InitialPublicOfferingDetailsTable"/>
    <loc xlink:type="locator" xlink:label="InitialPublicOfferingDetailsLineItems" xlink:href="bctg-20210331.xsd#bctg_InitialPublicOfferingDetailsLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ProposedOfferingDisclosureAbstract" xlink:to="InitialPublicOfferingDetailsTable" order="1.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsidiarySaleOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="InitialPublicOfferingDetailsTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IPOMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IPOMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_IPOMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OverAllotmentOptionMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OverAllotmentOptionMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_OverAllotmentOptionMember" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="InitialPublicOfferingDetailsTable" xlink:to="InitialPublicOfferingDetailsLineItems" order="2.0"/>
    <loc xlink:type="locator" xlink:label="InitialPublicOfferingOfPublicShares" xlink:href="bctg-20210331.xsd#bctg_InitialPublicOfferingOfPublicShares"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="InitialPublicOfferingDetailsLineItems" xlink:to="InitialPublicOfferingOfPublicShares" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="InitialPublicOfferingDetailsLineItems" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharesIssuedPricePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesIssuedPricePerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="InitialPublicOfferingDetailsLineItems" xlink:to="us-gaap_SharesIssuedPricePerShare" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="InitialPublicOfferingDetailsLineItems" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredOfferingCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredOfferingCosts"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="InitialPublicOfferingDetailsLineItems" xlink:to="us-gaap_DeferredOfferingCosts" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AmortizationOfDeferredSalesCommissions" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfDeferredSalesCommissions"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="InitialPublicOfferingDetailsLineItems" xlink:to="us-gaap_AmortizationOfDeferredSalesCommissions" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/RelatedPartyTransactionsDetails">
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionsAbstract"/>
    <loc xlink:type="locator" xlink:label="RelatedPartyTransactionsDetailsTable" xlink:href="bctg-20210331.xsd#bctg_RelatedPartyTransactionsDetailsTable"/>
    <loc xlink:type="locator" xlink:label="RelatedPartyTransactionsDetailsLineItems" xlink:href="bctg-20210331.xsd#bctg_RelatedPartyTransactionsDetailsLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionsAbstract" xlink:to="RelatedPartyTransactionsDetailsTable" order="1.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredRevenueArrangementTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredRevenueArrangementTypeAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsTable" xlink:to="us-gaap_DeferredRevenueArrangementTypeAxis" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="DeferredRevenueArrangementType_Domain" xlink:href="bctg-20210331.xsd#bctg_DeferredRevenueArrangementType_Domain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredRevenueArrangementTypeAxis" xlink:to="DeferredRevenueArrangementType_Domain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="AdministrativeSupportAgreementMember" xlink:href="bctg-20210331.xsd#bctg_AdministrativeSupportAgreementMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredRevenueArrangementTypeAxis" xlink:to="AdministrativeSupportAgreementMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsidiarySaleOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PrivatePlacementMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrivatePlacementMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_PrivatePlacementMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="FounderSharesMember" xlink:href="bctg-20210331.xsd#bctg_FounderSharesMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="FounderSharesMember" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IPOMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IPOMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_IPOMember" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementEquityComponentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="FounderSharesMember_0" xlink:href="bctg-20210331.xsd#bctg_FounderSharesMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="FounderSharesMember_0" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsTable" xlink:to="RelatedPartyTransactionsDetailsLineItems" order="4.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" order="0.0" preferredLabel="http://www.xbrl.org/2009/role/netLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockConsiderationReceivedPerTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockConsiderationReceivedPerTransaction"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_SaleOfStockConsiderationReceivedPerTransaction" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DividendsPayableAmountPerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DividendsPayableAmountPerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_DividendsPayableAmountPerShare" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="AggregateSharesOutstanding" xlink:href="bctg-20210331.xsd#bctg_AggregateSharesOutstanding"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="AggregateSharesOutstanding" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="DescriptionOfInitialStockholders" xlink:href="bctg-20210331.xsd#bctg_DescriptionOfInitialStockholders"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="DescriptionOfInitialStockholders" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharesIssuedPricePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesIssuedPricePerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_SharesIssuedPricePerShare" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="AggregatePurchasePrice" xlink:href="bctg-20210331.xsd#bctg_AggregatePurchasePrice"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="AggregatePurchasePrice" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1" order="7.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UtilitiesOperatingExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UtilitiesOperatingExpense"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_UtilitiesOperatingExpense" order="8.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="AggregatePrice" xlink:href="bctg-20210331.xsd#bctg_AggregatePrice"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="AggregatePrice" order="9.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesIssuedForServices"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" order="10.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_DebtInstrumentConvertibleConversionPrice1" order="11.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesIssued"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_SharesIssued" order="12.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
    <loc xlink:type="locator" xlink:label="SharesSubjectToForfeiture" xlink:href="bctg-20210331.xsd#bctg_SharesSubjectToForfeiture"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="SharesSubjectToForfeiture" order="13.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="PercentageOfIssuedAndOutstandingShares" xlink:href="bctg-20210331.xsd#bctg_PercentageOfIssuedAndOutstandingShares"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="PercentageOfIssuedAndOutstandingShares" order="14.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="LoanAmount" xlink:href="bctg-20210331.xsd#bctg_LoanAmount"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="LoanAmount" order="15.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentFaceAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_DebtInstrumentFaceAmount" order="16.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentUnusedBorrowingCapacityFee" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentUnusedBorrowingCapacityFee"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="RelatedPartyTransactionsDetailsLineItems" xlink:to="us-gaap_DebtInstrumentUnusedBorrowingCapacityFee" order="17.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/CommitmentsandContingenciesDetails">
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="CommitmentsandContingenciesDetailsTable" xlink:href="bctg-20210331.xsd#bctg_CommitmentsandContingenciesDetailsTable"/>
    <loc xlink:type="locator" xlink:label="CommitmentsandContingenciesDetailsLineItems" xlink:href="bctg-20210331.xsd#bctg_CommitmentsandContingenciesDetailsLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="CommitmentsandContingenciesDetailsTable" order="1.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsidiarySaleOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CommitmentsandContingenciesDetailsTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="ProposedPublicOfferingMember" xlink:href="bctg-20210331.xsd#bctg_ProposedPublicOfferingMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="ProposedPublicOfferingMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OverAllotmentOptionMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OverAllotmentOptionMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_OverAllotmentOptionMember" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CommitmentsandContingenciesDetailsTable" xlink:to="CommitmentsandContingenciesDetailsLineItems" order="2.0"/>
    <loc xlink:type="locator" xlink:label="DiscountPerShare" xlink:href="bctg-20210331.xsd#bctg_DiscountPerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CommitmentsandContingenciesDetailsLineItems" xlink:to="DiscountPerShare" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentFaceAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CommitmentsandContingenciesDetailsLineItems" xlink:to="us-gaap_DebtInstrumentFaceAmount" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharePrice" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharePrice"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CommitmentsandContingenciesDetailsLineItems" xlink:to="us-gaap_SharePrice" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherUnderwritingExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherUnderwritingExpense"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CommitmentsandContingenciesDetailsLineItems" xlink:to="us-gaap_OtherUnderwritingExpense" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="StockIssuedDuringPeriodShareNewIssues" xlink:href="bctg-20210331.xsd#bctg_StockIssuedDuringPeriodShareNewIssues"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="CommitmentsandContingenciesDetailsLineItems" xlink:to="StockIssuedDuringPeriodShareNewIssues" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/StockholdersEquityDetails">
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityNoteAbstract"/>
    <loc xlink:type="locator" xlink:label="StockholdersEquityDetailsTable" xlink:href="bctg-20210331.xsd#bctg_StockholdersEquityDetailsTable"/>
    <loc xlink:type="locator" xlink:label="StockholdersEquityDetailsLineItems" xlink:href="bctg-20210331.xsd#bctg_StockholdersEquityDetailsLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityNoteAbstract" xlink:to="StockholdersEquityDetailsTable" order="1.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementEquityComponentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StockholdersEquityDetailsTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_CommonStockMember" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StockholdersEquityDetailsTable" xlink:to="StockholdersEquityDetailsLineItems" order="2.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StockholdersEquityDetailsLineItems" xlink:to="us-gaap_PreferredStockSharesAuthorized" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StockholdersEquityDetailsLineItems" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StockholdersEquityDetailsLineItems" xlink:to="us-gaap_CommonStockSharesAuthorized" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StockholdersEquityDetailsLineItems" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="DividendPerShare" xlink:href="bctg-20210331.xsd#bctg_DividendPerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StockholdersEquityDetailsLineItems" xlink:to="DividendPerShare" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="AggregateSharesOutstanding" xlink:href="bctg-20210331.xsd#bctg_AggregateSharesOutstanding"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StockholdersEquityDetailsLineItems" xlink:to="AggregateSharesOutstanding" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
    <loc xlink:type="locator" xlink:label="CommonStockOutstanding" xlink:href="bctg-20210331.xsd#bctg_CommonStockOutstanding"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StockholdersEquityDetailsLineItems" xlink:to="CommonStockOutstanding" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="CommonStockSubjectToPossibleRedemptionShares" xlink:href="bctg-20210331.xsd#bctg_CommonStockSubjectToPossibleRedemptionShares"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="StockholdersEquityDetailsLineItems" xlink:to="CommonStockSubjectToPossibleRedemptionShares" order="7.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/FairValueMeasurementsDetails">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueDisclosuresAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsHeldInTrustCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsHeldInTrustCurrent"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_AssetsHeldInTrustCurrent" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/PrivatePlacementDetails">
    <loc xlink:type="locator" xlink:label="PrivatePlacementDisclosureAbstract" xlink:href="bctg-20210331.xsd#bctg_PrivatePlacementDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="PrivatePlacementDetailsTable" xlink:href="bctg-20210331.xsd#bctg_PrivatePlacementDetailsTable"/>
    <loc xlink:type="locator" xlink:label="PrivatePlacementDetailsLineItems" xlink:href="bctg-20210331.xsd#bctg_PrivatePlacementDetailsLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="PrivatePlacementDisclosureAbstract" xlink:to="PrivatePlacementDetailsTable" order="1.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsidiarySaleOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="PrivatePlacementDetailsTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PrivatePlacementMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrivatePlacementMember"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_PrivatePlacementMember" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="PrivatePlacementDetailsTable" xlink:to="PrivatePlacementDetailsLineItems" order="2.0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="PrivatePlacementDetailsLineItems" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/label"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharesIssuedPricePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesIssuedPricePerShare"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="PrivatePlacementDetailsLineItems" xlink:to="us-gaap_SharesIssuedPricePerShare" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="PrivatePlacementDetailsLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/IncomeTaxesDetails">
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
  <presentationLink xlink:type="extended" xlink:role="http://www.bctg.com/role/DocumentAndEntityInformation">
    <loc xlink:type="locator" xlink:label="DocumentAndEntityInformationAbstract" xlink:href="bctg-20210331.xsd#bctg_DocumentAndEntityInformationAbstract"/>
    <loc xlink:type="locator" xlink:label="dei_DocumentInformationTable" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_DocumentInformationTable"/>
    <loc xlink:type="locator" xlink:label="dei_DocumentInformationLineItems" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_DocumentInformationLineItems"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentInformationTable" order="1.0"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationTable" xlink:to="dei_DocumentInformationLineItems" order="1.0"/>
    <loc xlink:type="locator" xlink:label="dei_EntityRegistrantName" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityRegistrantName"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityRegistrantName" order="0.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="dei_DocumentType" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_DocumentType"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentType" order="1.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="dei_AmendmentFlag" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_AmendmentFlag"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AmendmentFlag" order="2.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="dei_AmendmentDescription" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_AmendmentDescription"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AmendmentDescription" order="3.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="dei_EntityCentralIndexKey" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityCentralIndexKey"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityCentralIndexKey" order="4.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="dei_EntityFilerCategory" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityFilerCategory"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityFilerCategory" order="5.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="dei_EntitySmallBusiness" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntitySmallBusiness"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntitySmallBusiness" order="6.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="dei_EntityEmergingGrowthCompany" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityEmergingGrowthCompany"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityEmergingGrowthCompany" order="7.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="dei_EntityExTransitionPeriod" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityExTransitionPeriod"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityExTransitionPeriod" order="8.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <loc xlink:type="locator" xlink:label="dei_EntityIncorporationStateCountryCode" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityIncorporationStateCountryCode"/>
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityIncorporationStateCountryCode" order="9.0" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </presentationLink>
</linkbase>
