Shaders not appearing in game menu (NextUI/Brick)

In NextUI, no matter what I try, whenever I try to select shaders in the ingame options menu (under Shaders), it tells me that shaders aren't available because it can't find a Shaders folder.

I've tried putting Shaders folders in a handful of places, but no matter how many different spots I store them in the SD card, I get the same error message across every console.

Where am I supposed to put the folder(s)? Does each console need a separate folder? I've looked around and found multiple guides for how they work and what parameters to use but nothing for the location in the file system.