Advanced Search adapter for Solr - Hidden query filter to limit results

I want to restrict the results of a custom search page with advanced search and Solr.

The page slug is “search”

When I add ?q=item_set_dcterms_title_ss:"Togo-Presse" to the URL (Recherche · Collection Islam Afrique de l'Ouest · IWAC), I correctly get all the items that belong to that particular item set.

However, I’m unable to enter the correct value in the “Hidden query filter to limit results” field. I’ve tried different combinations, but I always get 0 results.

Thank you in advance for the help!

I don’t expect that this is the solution, but I was not sure why you have put an equals sign “=” at the end of your hidden query filter. I cannot see anything in the documentation of the module as to what the format of the hidden query filter is supposed to be!