In our Effeciency Dashboard, the only other options we have besides Global are groups which are comprised of physical systems. So I have a group called FAS3170 which contains the two nodes for that filer. That shows in my drop down list for the Effeciency Dashboard. I have other groups created, e.g., Vmware-NFS which work fine within the Operations Manager, but are not listed within the Effeciency Dashboard.
Perhaps the Effeciency Dashboard only works with groups comprised of physical systems/hosts.