Staff Only Wiki, but want to set limits on what they can read only or edit?

Setting wiki up for staff only, but want to set limits on what they can read-only or edit?

Only registered users are able to login and view content as using 'Restricted Site Access' plugin.

Setting up a staff as Subscriber means they can only view content, join in a discussion on a wiki, or add a comment on a normal post.

A Contributor can edit/create wikis and also create posts which will be submitted for review of an admin before been published.

But want to make some Wiki Categories limited to certain logins and some logins read-only in certain areas.

Thanks.