Having issues with Azure AD B2C custom policies. Trying to get "groups" using Graph API

Question

I am using Azure AD B2C working with it's custom policies. What i am trying to achieve is. I want to get my groups in which my user is added. I have a userinfo endpoint in which i am trying to get itenter image description here. When i use my graph api to fetch the groups. it's returning raw json

<ClaimType Id="groups">
                <DisplayName>groups</DisplayName>
                <DataType>stringCollection</DataType>
                <DefaultPartnerClaimTypes>
                    <Protocol Name="OAuth2" PartnerClaimType="groups" />
                    <Protocol Name="OpenIdConnect" PartnerClaimType="groups" />
                </DefaultPartnerClaimTypes>
            </ClaimType>


        <TechnicalProfile Id="REST-GetGroupMembership">
          <DisplayName>Get user's groups using Graph API</DisplayName>
          <Protocol Name="Proprietary" Handler="Web.TPEngine.Providers.RestfulProvider, Web.TPEngine, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
          <Metadata>
            <Item Key="ServiceUrl">https://graph.microsoft.com/v1.0/users/{objectId}/transitiveMemberOf?$select=id,displayName</Item>
            <Item Key="SendClaimsIn">Url</Item>
            <Item Key="AuthenticationType">Bearer</Item>
            <Item Key="UseClaimAsBearerToken">bearerToken</Item>
            <Item Key="IncludeClaimResolvingInClaimsHandling">true</Item>
            <Item Key="ClaimResolverUrlFormatting">true</Item>
            <Item Key="ResolveJsonPathsInJsonTokens">true</Item>
          </Metadata>
          <InputClaims>
            <InputClaim ClaimTypeReferenceId="objectId" /> 
            <InputClaim ClaimTypeReferenceId="bearerToken" /> 
          </InputClaims>
          <OutputClaims>
              <OutputClaim ClaimTypeReferenceId="groups" PartnerClaimType="value" />
          </OutputClaims>
          <OutputClaimsTransformations>
            <OutputClaimsTransformation ReferenceId="CheckIfMemberOfAllowGroup" />
          </OutputClaimsTransformations>
          <UseTechnicalProfileForSessionManagement ReferenceId="SM-Noop" />
        </TechnicalProfile>






This is how i am getting my response in token:

 "groups": [
    "{\r\n  \"@odata.type\": \"#microsoft.graph.group\",\r\n  \"id\": \"3bae6asfjkhs\",\r\n  \"displayName\": \"certified\"\r\n}"
  ],


And in postman response as:

{
    "group": "System.Collections.Generic.List`1[System.String]"
}