Theoretically yes, but I'm not sure that is a good option. Removing / adding groups from /to groups would result quite an explosion in indexing. I think you would have to re-index all the indirect memberships of each child of the member group. When adding group to group though we *might* just be able to get away with using ES's scripting language, but doesn't seem to be a better option for the removal case. But it was certainly in mind if the current option was a bottleneck. That, and Redis storage of memberships cache.