Hi, are you referring to this section? (Attached)
I'm not aware that you can add any other cloud storage options (such as box, Amazon etc) natively - Google is obviously android and Samsung has a partnership with Microsoft so allows OneDrive.
You can add multiple Google drive accounts by clicking the options (top right dots in the 'Files' app) - Google One is Google Drive.
For other 3rd party cloud storage their respective apps would have to be used.
I haven't tried to set up a network drive so maybe someone else can advise on that - the option is there though.
Storage is a pain, it's a losing battle as you'll always keep adding more and more! I ended up paying for 2tb Google One to last me a while
😏
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