conditional role assignment like in hrbac


is there any good rbac extension that supports the assignemt of conditional roles like explained in hrbac.

Hrbac seems to be unfinished/unstable for me. Do extensions like rights or rbam and so on support something like this. If not, are you interested in implementing it?

I dont know whether its the right approach, but I want to do somethink like this:

THere is a group identified through an id. This group is assigned somekind of groupeditor.

For groupeditors there should be a role, but that role is only for that group. and the user assigned editor for that group should be able to be assigned as editor to a different group aswell, so he gets a second role "groupeditor" for the other group.

adam is groupeditor for group 4

adam is groupeditor for group 5

becky is groupeditor for group 4

Business rules could be used for this, but that looks somehow confusing, because a user gets the role "groupeditor" once, but is only able to edit one grup at all, or able to edit more groups.

Do you see my point?