You need four tables to do this. Actually two tables and two aliases. All groups and users are stored in the OBJ_M_ACTOR table. Users have one type ID value and groups have another. To put users and groups together you need (if my memory is correct) OBJ_M_ACTORLINK. You will like OBJ_M_ACTOR where type ID = user to OBJ_M_ACTORLINK based on key values, then link OBJ_M_ACTOR where type ID = group to OBJ_M_ACTORLINK as well. Then the two copies of OBJ_M_ACTORLINK are linked together. I just don’t remember the exact column names used to do the linking.
There is a repository reference here on BOB that will probably help you do the actual SQL for the tables I’ve listed.
Dave Rathbun 
(BOB member since 2002-06-06)