Placing Category-Filteror Search Filter Box in Search-Results Page

Hello. I am stumped and I cannot seem to figure out how I can place a search-filter (or category filter plugin) Box in the search-results.html page. I cannot seem to find the search-results page in the list of pages when one edits a content box and its placement.

I was trying out also the refine Search box but I cannot seem to make it appear in the search-results.html pages.

I presume that the best place to put a category filter box or search filter box is in the search results.

The refine search appears on search results when you use the quick or advanced search. There is no search results page to place it in within your content box, use the category type page, example mines a used car site so i would place it in the used cars page.

The category filter appears when you are in a specific category (not using the quick or advanced search)

Thank you so much Chris! Now it has become clear! I now know where to put the particular boxes. Thank you so much for the clarification!