Hi Alan,
Thanks for your interest in our plugin!
There are actually two different ways of filtering. Thanks to the Tribe shortcode available with PRO, you, as an admin, will be able to choose which categories you want to be displayed. On the other hand, Filter Bar will allow your users to select which categories should appear.
Both plugins are independent; you don’t need PRO to use Filter Bar.
I hope this helps — please let me know if you need more clarification on this.
Cheers,
Jeremy