Granting access to specific tickets for specific users without granting access to entire queue

I’m trying to grant users access to tickets on a case-by-case basis without giving them access to the entire queue that the ticket is in.

I’d like the ability to make the user an Owner or an AdminCc and want them to receive Comments that go to Owners and AdminCcs.

The user has been granted the right to access RT and has been granted rights (is Privileged) but I can’t seem to find the right combo of rights on the queue to make this work.

In ‘Admin > Global > Group Rights’ apply the rights via the ROLES instead of SYSTEM > Privileged rights. For example if you gave ShowTicket to the Owner ROLE, and they do not have this right via the Privileged right, the logged in user would only be able to see tickets they owned.