Have you tried using "Groupings"? Groupings = Collection of Groups
Eg: Group 1, Group 2, Group 3, Group 4
Grouping A = group 1 & Group 4.
Grouping B = Group 3
Grouping C = Group 2
You have to enable "Grouping", once it is enable, look under "Visible" option. There should be a tick box for you to check and select which Grouping to allow the resource to.
Eg: Group 1, Group 2, Group 3, Group 4
Grouping A = group 1 & Group 4.
Grouping B = Group 3
Grouping C = Group 2
You have to enable "Grouping", once it is enable, look under "Visible" option. There should be a tick box for you to check and select which Grouping to allow the resource to.