I abused it in the past for aggregating every bitmask of CIDR, where the underlying data was by IP. So the groups were functions of the IP, one per mask level.

I abused it in the past for aggregating every bitmask of CIDR, where the underlying data was by IP. So the groups were functions of the IP, one per mask level. We needed aggregations of arbitrary levels and this worked relatively well. We also tried it using it for some reporting that was tied to organizational hierarchy - same intuition - the group sets included org, parent, grandparent, etc ...