Syncing from NAS User Homes folder to another user account

We have iphones used in the field to take pics/videos. We’ve assigned each iPhone as a user i.e. Field1, Field2, etc. on Synology that backups the media using Synology Photos.

Scenario 1:
Individual users are taking field photos from the iphone. Synology Photos backups the media to user’s /home folder.

  • How do I sync the individual user’s /home folder to another user’s /home folder?

Scenario 2:
Individual users can use CloudSync and sync with their Google Drive to the user’s /home account.

  • How do you sync the other way from the user’s /home account to Google Drive?

I’m using the DS File app on my iPhone and configuring it to backup to a particular subfolder on one of the shares on my NAS. I am going to be setting my wife’s iPhone similarly but just to a separate directory. The app keeps track of which photos have been backed up and allows one to clean out those that have been from the phone.

In my case, the folder the photos are saved to is one that I periodically go through to determine where the picture belongs. It is a temporary spot to do a phone dump. I can then ask does it belong in Synology Photos, is it something that belongs somewhere else, or is it some temporary picture taken that is no longer relevant, such as a pic to remind one of where the car was parked in an unfamiliar parking garage or the like.