I am not really following how this relates to the other topic at all. There are built in categories for Staff in every Discourse. If you are a moderator you already have access to this category, and only staff can read/post there.
I do not understand this request. Can you explain the need with specific, real world, actual examples?
Right now reading what you wrote I am super confused. Forget the “feature”, explain the need. Use real examples. What is the goal?