Advanced Search is hidden. You have to use something else to get to it. Like emerald's tag/genre trick from a drama/movie page. The one I stumbled on, and the only one I was able to find my way back to when I was new here, is via Explore > Top Movies (or Top Shows).
It's a remarkably poor design flaw, one of many. Search filters really shouldn't be buried a layer down on a database site. Poor user experience and it will generate misleading statistics for the devs, but it's what they've chosen to do.
Anyway, that's how it works. Bookmark it or find the trick you'll remember to get there.
Within Advanced Search itself, you have options to specify country and other things. You can include a genre by clicking once, so there's a green check next to it, or exclude a genre by clicking it twice, so there's a red X. You can also include or exclude a particular tag or theme in their section if you want.