[Zope] stopping acquisition

I have a folder setup like the following top top\current top\past in the top folder I have a script that includes container.current.superValues('Structured Document') works okay except (thats the big word) that it is also lists structure documents in the top folder. is there some way to limit the scope that superValues looks? I thought buy putting it in current it would limit it's enumeration of structured documents to just that...