I can have group of "switches" and add in all my switches, I can also have a group "routers" and add in all the routers. I want to have a group called networking add in routers and switches in to that group, similarly add hosts to "LINUX Servers" and "Windows Servers" and then have a group called servers containing those two sub groups.

The sub groups would inherit characteristics from above unless specifically defined in the subgroup. Example, escalation paths can be defined at networking because I have the same network administers, but monitoring templates are different and defined at the sub group.

A group can be part of more then one group. Routers are part of the "networking" group and they are part of the "marketing" group.