Select 
* 

from 
groups 

where 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 = 2 or a.WParentGroup2ID is null)
		)
	)
