I'd like to note that this kind of filtering is already possible in commons:Special:MediaSearch. Adding something like "is in Category: ________" to that interface might already do the trick. (That probably should include a setting/slider for how many levels of subcategories to include.) Make it accessible from each category page with a link titled something like "search in this Category". Shouldn't be too hard to implement, I guess? --El Grafo (talk) 16:07, 26 January 2023 (UTC)[reply]
Trick: click in a category on the tab "More" and then on "Search not in category". Now you get a search page. Remove the first part of the search string, including the "-" in -incategory:"Name_category". Now you are left with incategory:"Name_category" and you can edit your search the way you want to. JopkeB (talk) 10:05, 11 February 2023 (UTC)[reply]
Without this feature, a lot of users are trying to do this by creating additional layers of categorization that if fine for one perspective of filtering, but can make the categories a mess for everyone else. Hopefully, a good filtering tool will help reduce the urge to create a bunch of extra categorization. Ideally, if done well and integrating structured data, over time we can greatly simplify the category structure, but that would remain to be seen after this feature is implemented. In any case, I think this would be a very good tool to add. Joshbaumgartner (talk) 22:50, 10 February 2023 (UTC)[reply]
I would like to piggyback this idea of an advanced search engine using structured data. I don't understand why we have structured data if we can't use them to make complex searches. Or am I missing a tool ? BotaFlo (talk) 19:20, 19 February 2023 (UTC)[reply]
Support Don-vip (talk) 21:39, 10 February 2023 (UTC)