We have a number of ranks, and access to forums is gained then lost depending on that rank. So level 2 gets forum 2, but when you go up to level 3 you get forum 3 but lose 2. It's a popular feature.
That wasn't an issue with vBulletin as I could remove people from usergroups - however I am finding I'm a bit stuck as removing access is difficult.
For example if I have grant on level 2 and revoke on level 3, grant remains because of the hierachy so even when they are in group 3 they retain access to group 2.
I can't use never however - because just to complicate matters there is a group that has access to all forums.
Is there any way to achieve what I want?