We have a decent document for creating security views using $$USER_ROLES to dynamically determine if a user is authorized to access certain documents/fields in a collection. I'm referring to this:
https://www.mongodb.com/docs/manual/reference/operator/aggregation/setIntersection/#retrieve-documents-for-roles-granted-to-the-current-user

Unfortunately, this seems to only appear as an example in the use of $setIntersection and I would think that security views using $$USER_ROLES deserves its own document detailing this capability.