Default How do you stop a folder from being seen by android

What I wanna do is make a single backup folder, then have stuff like ringtones, notifications, alarms, and pics under that folder.

What I want to prevent is ringtones and pics from being seen twice by the system. So I wouldn't say see a ringtone called ring1 twice when picking a ringtone, and I wouldn't see a pic1 twice in gallery.

I know you can put a .nomedia in the folder you want to hide from the system, but can you do it in a single folder and it keeps sub folders also from being seen?

Example:

Backup/
/ringtones
/notifications
/alarms
/pics
/apps

This is just a small example, but if I put a .nomedia under backup root, will that then hide ringtones, notifications, alarms, and pics with the single .nomedia file?

End result would be:

Backup/.nomedia (file)
/ringtones
/notifications
/alarms
/pics

Will that work, or do I need a .nomedia in each folder?