If you create a saved search in a group, and select as search criterion "saved search" you get a drop down menu. This drop down menu only includes the saved searches from my main library, but not those of the group in which I created the saved search itself.
Obviously, this is not very helpful. I assume it is a bug, and it should (preferably) give a drop down menu with either ALL saved searches, from all groups and the main library, or it should at least give a drop down menu with the saved searches from the group, rather than the main library.