Hi Maginos,
I found that on the forum : help.nextcloud.com
I think this might help. To sum up, there can only be one “NEXTCLOUD_MOUNT” but it is possible to use the “mount” command.
In your case the mount command should look like this:
mount /mnt/user/xyz/ /destination/folder/on/nextcloud/app
In the past, I’ve encountered a problem when adding a volume to docker. I had to remove the last slash before the colon.
'/mnt/user/photo':'/mnt/user/photo/':'rw'
Have a nice day,
Sharkof