Product Filter module for XC5 is really not what it seems to be.
If you test drive the demo site -
https://demostore.x-cart.com/ - you will see the filters show on categories and search pages, nice look and every filter works on selection to filter products in the background and show results.
But this is only because it is combined with CloudSearch module. This is not mentioned anywhere.
The Product Filter module on its own works ONLY on current category with products. It will not show and work on search result pages.
So when you navigate to category with 5 products you will see some filters you can apply to them to narrow results.
When you do a search for some term and you have 200 products returned there is no Product Filter to narrow your search results further.
Also - the Product Filter module requires additional click on filter selection - Show Products button - in order to run the filter.
In its current stage the Product Filter module looks almost useless since it can only work on category with products. Being able to filter search results is very important functionality which is missing from this module.
I would understand if the cart doesn't have search functionality by default and thus the module will not include it. But that's not the case here. It is far more important to be able to filter products on search results than products on category page.
I am still waiting on XC to confirm this but from my testing, examining the code and going back and forth with them on the issues I believe this is exactly the case here.
Very disappointed in this module.