How to filter visualization using Query DSL

Hi everyone, I have a string field called “valuation_date” in the index pattern which is really YYYYMMDD - i.e. 20220331, 20220404
My client wants to filter this visual where valuation_date = current quarter. I’m already using “event_dt” as my timefield for this index pattern.

What is the best way we can do this? The “edit filter” option doesn’t allow me to do this easily, and I am unfamiliar with how Query DSL works (never worked with JSON before…). Appreciate any assistance! Thank you in advance.