If you are indeed using BO-XI, then your query would be similar to this…
Select SI_ID, SI_NAME, SI_USERFULLNAME From CI_SYSTEMOBJECTS Where SI_KIND='User'
And SELECTUSINGPROPERTY(2,SI_ID,SI_GROUP_MEMBERS,SI_ID) Order By SI_NAME
That assumes you have an Administrators type group, and that you know the ID of that group (you can get that thru the CMC or by running a query to find your group id.
My Administrators group is queried with the “2” in the example above.