[Zope] Assiging Owner Roles to subfolders

Ok - newbie here, This may be a basic question but I can't figure it out. I have series of folders that I want different groups to be able to modify the contents of (including the sub-folders). I thought the easy way to do this is to create the folder and then share the contents of the folder with the group of interest. But for some reason, it doesn't automatically share all the subfolders with the user. Any ideas on how to do this would be appreciated. thanks in advance, Dan