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?