[Zope] Tree tag to show only objects that evaluate from a expression

Zopists, I am studying the documentation on the tre tag and looking at the source, and I'm not sure how to get this to work. I am using <dtml-tree expr="PARENTS[1]"> to get the tree tag of a folder above the current folder. I would like to only display the tree of objects in that folder that met a certain criteria. I have tried branches_expr=objectValues(etc...), but I need it to display only the tree of a few of that particular meta_type if they qualify, not all of them. Any ideas? Gradually wrangling the beast, -- Jason Spisak webmaster@hiretechs.com