So each relation is to the same sheet? I was understanding it as 2 similar relations to separate sheets, but with the same column used for each relation.
Anyhow, what I would do is create columns in the sheet used for your list. These could either be Single Value columns or Relation/Lookup columns that will bring in your filter criteria into your listing sheet. Then create IF/THEN columns then check each filter criteria. Finally create a final IF THEN column then checks if all other conditions are true and returns a final true or false value that you can use to filter your list.
In the end you’ll only need a single relation, but the true false values in the related listing sheet will determine how you filter that list, based on your filter selections.