Is it possible to assign a Role to a Group?
I am looking for a bulk solution to assign all staff in a Business Unit to a few groups relevant.
I'm not sure whether either of these will achieve the result you're after as you don't say why you want to do this... if it's so staff get notifications from processes within the group then that should happen anyway if you've assigned the correct roles within the process maps.
The only way I've found to add a role to a group is to add it as a process group editor.
Alternately you could perhaps create an overview diagram for the process group and add the role as an assigned responsibility in the overview diagram.