I am trying to add custom filter to layer navigation. Basically I didn't have any problem with displaying it on navigation sidebar but collection filtering is now the problem.
I have filter which is NOT product attribute and that filter has two possible items. Each item should be filtered by two product attributes.
E.g: New collection item should filter by attribute1 AND attribute 2...
I overriden search_request.xml and added my new filter item but I am not sure what is the problem with collection filtering and returning total number of products ( count item of filter ). I am using Amasty layered navigation which does some custom filtering but I am unable to find a place where collection filter conditions should be added.
Any help is appreciated.