Am I interpreting your suggestion correctly that you want to be able to filter the content of your library based on the physical drive they’re stored on?
I’m not exactly sure the concept of a „disc drives“ is transparent to Plex. You could e.g. assign different paths to a library that are physically stored on the same drive. You could also mount drive groups from a NAS as a single „drive letter“ / mount point on your OS where the physical disc drives are completely intransparent to the app.
There’s already an existing suggestion discussing an option to be able to filter the library based on certain elements of their paths… I guess that should also cover a use case where you want to filter videos based on just their drive letter? If so, I suggest you comment/vote in that thread in order to help us avoid distracting or cannibalizing votes (and closing this thread as a duplicate).
Currently you should already be able to see that information in 3rd party apps like WebTools-NG.
