Right, so there’s this awesome thing called WP Hooks Finder WP Hooks Finder – WordPress plugin | WordPress.org. It’ll quickly allow you to find out which filter or action to use, It’ll show the available filters or actions on the frontend and to use it simply hover over the admin bar and click the show actions or filters.

When you click the filter it’ll do a Google search for said filter and explain what parameters are involved. And there you quickly found a filter without going through the code file.