I know it is not the idea of Workspaces, but one of our use case.
I want to share a workspace. The receiver should not be able to even see (and of course work with) the given dimensions, metrics and segments. All options i see with the permission regulation finally generates not such an outcome.
You can manage the dimensions , metric, report suite access along with workspace permissions through a product profile in Experience cloud > Admin console. Users would be able to access workspace only for listed dimensions/metrics/report suites.