I was planning to make a video, but I just haven’t found the time. The UI for RAW Power’s split toning is fairly similar to Lightroom’s, so videos on those are probably useful.
You can work with highlights, or shadows, or midtones. You can tint them independently.
You also have the ability to work with the luminance (brightness) of highlights, or shadows, or midtones independently.
Finally, the Balance slider controls the definition of “highlights” vs. “shadows” that is, how dark must something be to be shadow (and thus the inverse is a highlight pixel).