Hide music from list of alarm, notifications, and ring tone files How to keep my music and alarm files separate suggested I could nut an empty file named .nomedia in my top Music directory to prevent Music files from being seen by the Alarm app when I create a wake-up alarm. Well, that does not work and when I set an alarm and wish a non standard alarm sound, I must scroll through over a thousand music files to find the Alarm sound file. Same happens with ring tones and notifications. How do I prevent Music files from appearing on my OnePlus 7pro w/ Android 10?
I had the same problem on my OnePlus 7. It's irritating that the Oxygen OS pick menu doesn't have a  search () option.
To over come this I use Ring Tone Maker. You search for a tone, long press and from 3 dots menu on right, choose to set it as a ring/alarm/notification tone. Drawback of this approach is that you can't find default tones in this app. If your device is rooted, you could locate those files and copy in some folder that would show up on this app