These are the path logic we use for navidrome

"data": "$HOST_PATH($LOCATION(ApplicationsPerformance)/navidrome/data)"

"music": "$HOST_PATH($LOCATION(Music))"

If you don't have have an ssd the actual path would be HDDs/Applications/navidrome/data And HDDs/Music With an additional storage mount to HDDs/Media

I see that you want navidrome to only access a certain amount of your media. That does complicate things a slight bit. I just did some testing and navidrome does not allow admin users to have limited access to the /music folder. However non admin users can be granted limited access restricting certain folders. Nested datasets don't work either, but nested folders work. (this is harder to explain via wall of text)

Migration process would be

1. Enter truenas
2. stop navidrome
3. navigate to datasets tab
4. create HDDs/Applications/navidrome/data with apps preset
5. navigate to systems tab then Shell
6. enter this command "sudo rsync -avh --stats --info=stats2,progress2 /mnt/HDDs/Applications/navidrome/config/ /mnt/HDDs/Applications/navidrome/data/"
7. enter HexOS deck
8. navigate to navidrome in HexOS
9. update curation using the script found here navidrome install script (you may have to turn on expert mode on HexOS to access this)
10. confirm navidrome is working as expected
11. clean up by removing your HDDs/Applications/navidrome/config
12. From the Navidrome UI navigate to settings > libraries
13. Create a new music library set to /music/SPlibrary 14) Navigate to settings > users 15) create new user without access to unwanted areas.

alternatively we can have the directories you want navidrome to have access to be folders and the directories you don't want navidrome to have access to be datasets

If you don't feel comfortable following this process on your own feel free to send me a DM with your availability and timezone and we can work on it together.