I came here to figure out the same thing. I'm trying like crazy to figure out Content Directory Overrides. I read [the documentation](https://docs.libretro.com/guides/overrides/), and it made sense; but it doesn't seem to be saving the way it's supposed to. If I understand this correctly, in the retroarch config directory (specified under *settings* > *directory*), there should be a folder named after the core, and within, there should be a file named <coren ame>.opt. This should hold the overrides for that core, including the directory overrides. Right?
Well, I found the file, but my Content Directory Overrides don't seem to be appearing in that file when I save/create an over-ride.
Ultimately, what I'm trying to accomplish is to have SameBoy emulate the OG GameBoy for GB Games that were **not** Super GameBoy enhanced, Emulate Super GameBoy for the GB games that were enhanced for SGB, and emulate Game Boy Color for GBC games. So I put the three types of games in different rom directories, and I'm trying to create a Contend Directory Override for each of them. Just doesn't seem to be taking. Any idea why?