Select  * from groups where WParentGroup2ID in (
Select  c.WGroupid from groups c where c.WParentGroup2ID in (
Select  b.WGroupid from groups b where b.WParentGroup2ID in (
select a.WGroupid  from groups a where a.WGroupTypeId = 26 and (a.WParentGroup2ID = 1 or a.WParentGroup2ID is null))
)
)
 