Filter according to already set search terms

Hello,

Wondering if anyone could help

So I currently have a site with a main search bar across the top – so the user types in say “hairdresser” they then get brought to the product result page. One of the filters on my woof is “location” so when they click on their location I ideally want their already searched term to be narrowed down via that filter. So if they chose London they would then see all hairdresser terms that are also tagged with london.

At the moment when they click on london it restarts the search and shows them ALL products tagged with london

Any ideas on how to fix this?