How to edit page layout of content search webpart items?

I have a list of items that I'm getting through a content search web part and content catalog source. I understand where to get the display template to edit for these results, I can't seem to find how to edit the page that the item links to.

I have set the "Catalog Item Url Behavior" to "Make URLs relative to this site" in Catalog Source Settings page.

This is the page I'm trying to edit.