Thanks Marc, I figured it was something like this. Because we have limited membership to these groups, in our case students, I have started a database with a field for members and I am populating this so the moderators will have this list, in their category, with live links on the listing too, very helpful for us. It also gives a field for keeping notes, like evaluations of student progress too.
I looked at clubs which does list the members and could set it up that way too, as I'm registering the students I can have things set up for them before I notify them of their membership, but I think the database is better for us.
We have 15 classes or groups of students in 4 schools with 5 groups of moderators and so far your system and its layers of permissions is handling the complexity and its working, each class only sees its own version of the site, forums, galleries, calenders, yet there is course material that is common to them too, in databases with categories.