Seen it before but now it isn't there. Supposed to be there when you go to contacts and hit the BB button, right? Is there another setting somewhere for this?
There is a number of menu commands in contacts that only show up if you click the contact icon in the home screen, filter is one of them.
I had hidden the contacts icon because I thought I didn't need it. I have been accessing the contacts via the phone screen and also holding down the green button. In each case the menus are missing filter, delete, add, etc.
To me this is another bug. Any time you click "contacts" you should get the full contact menu.