but for prisma it seems those nested aggregates isnt available, is there any solution for this? thanks in advance

You will need to resolve them using the aggregates, here is an example: https://github.com/javascript-af/javascript-af/blob/ffba83c9e70c59fdc44f1eff1ee9a27c9487d0b8/packages/backend/src/resolvers/Repo/Repo.ts#L15