You need to add
tblADusers a second time to your report under a different alias and join it's
ADObjectID column to the first table's
ManagerADObjectID column. In the report below we did it two times for two levels of managers.
Select tblADusers.Firstname,
tblADusers.Lastname,
tblADusers.Description,
tblADusers.Department,
tManager.Displayname As Manager,
tManagersManager.Displayname As [Manager's Manager]
From tblADusers
Left Join tblADusers tManager On tManager.ADObjectID =
tblADusers.ManagerADObjectId
Left Join tblADusers tManagersManager On tManagersManager.ADObjectID =
tManager.ManagerADObjectId
Order By tblADusers.Firstname