Add a filter option to show me products that have the bottom-most category set to X (eg:beers)

[DanieliusAsm]

Problem

When I want to clean up a giant category like beers it becomes difficult to do so. I already cleaned up IPA's so I would not want to see these products when im browsing beers parent category.

Proposed solution

A filter option to show me products that have the bottom-most category set to beers. Meaning that If a beer has category: beer->ales this beer wont be shown to me after I apply a filter.

This would also allow to easier fix a common issue where non-alcoholic beers are constantly assinged to beers category.