the real name is Favorite relays list, I understood after "clear" it's like reset, default settings
Discussion
Default settings on that search page's controls, not on any of the lists in the controls. If you want to CRUD (create, read, update, delete) lists, you have to use the settings modal (not shown, entered by clicking on the profile pic in the top-right corner).
You can only filter-by-list, here.