Groups are collections of users that can be used to control access to categories. Could you just give your staff access to all the categories without requiring them to join a group? (add the employees group to all of those categories). Or is there something else you’re doing with the group?
I doubt that this is going to make it into core soon, but a plugin could do it.
Apologies if these suggestions are what you know already and what you really want is the feature.