There should be a Snap Plug to add specific directories outside $HOME to the list of allowed directories for a snap

[Tim Edwards]

Currently when using a desktop application inside of a snap package it's possible for that application to access files under /home/<username> by using the Home plug.

It's not currently possible to have it access any other directories outside of your $HOME, even directories you own.

Example:
I use Filebot to rename movie and TV show files so my media server (Emby) can pick them up and find the correct metadata. My movie/TV show files are on a Btrfs formatted partition on a separate internal hard drive in my compter - i.e not part of my home directory (since they're too big).
The only current way to have Filebot access this Btrfs partition is to install it in --devmode, but that negates many of the benefits of snap packages in the first place.

[Oliver Grawert (ogra)]

A workaround you can use is to mount your disk under /media/$USER/ and use the removable-media interface to give your app access to this.

[John Lenton (chipaca)]

I agree this would be nice.

[Borim (borim)]

This limitation is the reason why I rarely use snaps. It make using a lot of programs way too cumbersome.

When I want to edit a file, that is normally accessible, than I do not want to mount a filesystem in the snap or copy it into my home directory.
The copy to home directory approach have the additional drawback, that the file have to copied back to it actual location -.-

My solution is to stick to the native program version, at least it works.