Hello Adam,
you can probably implement a simple structure just using identity schemas, but for something like a SaaS tenants etc.
I would recommend to take a look at Ory Keto.
Here is an article that goes into an implementation of RBAC
https://gruchalski.com/posts/2021-05-15-rbac-with-ory-keto/
Does that answer your question? I feel you were looking for some different advice 😅