I'm using the ecommerce add-on and my products are organized in categories and sub-categories.

I use product sets to be able to show only products in one category or sub-category.

Let's say I want to show a product list of the top-purchased products in a category or sub category.

In other words how do I filter my list of products with 2 criteria instead of just one: sales statictics and product set at the same time?

Thank you