Please add the ability to use a different taxonomy for the Post Card filters. My scenario: I have a custom post type called Document with a primary category of Library, which determines where the documents should live. Then I have a secondary taxonomy (document category) for the library section where you would find this item.  Using the current features, I can only choose one or the other and this makes the filters useless (Library) or allows content from another library to be included (document category). The ability to choose which taxonomy drives the filters should allow for the correct layout. Using a post type of document, pull all the documents in a given library, and filter by the document categories.