[Zope] dtml-in question

Helloa all, pls. pardon me if my question is sily, i'm a newbie. :) in zope 2.3x with <dtml-in> tag, how to list the objects that has property "menu" ? in a particular folder? for example, i want to list objects that has "menu" property in folder = /products/books with a DTML_Method in folder = /products/music how to do that? thanks for your help ismet