Removing unused filters, views and groupings

While cleaning up our instance I manually removed any filters/views/groupings that were owned and shared with users that are no longer with the company. I was hoping to set up a quarterly process to clear these out but am not finding a great way to do that. I don't see where they are accessible within Fusion to identify filters/views/groupings. Anyone know a trick?

I also tried creating a filter report and setting it to only show those owned by users that aren't active BUT it came back with tons of results that are not showing in the master filter list in the setup area. Every user was showing an All Documents, Recent, _filter etc but I do not know where those are pulling from since they don't show in the master list. (photos attached. System only shows 2 document filters total but the report shows 2 different document filters for every user.