Hi +Hannah Poferl
What Andrew said.
Also, leave the & out in GA settings where you specify the parameters, so category is just filters1 without the &, for example.
If you can't navigate around the restrictions set by the search engine, you could also ask the developers to configure a virtual pageview when the search is used. This vp would then gather the query parameter and category parameters from the dynamic search string into something that GA can use.
Becomes a virtual pageview like