If you mean that you need to copy users' files from one user's OneDrive for Business to another users' OneDrive for Business, then you will need all these users' OneDrive for Business accounts. Then create the flow:
1. With the user1's account connection -> "OneDrive for Business - When a file is created"
2. With the user2's account connection -> "OneDrive for Business - Create file"
And you need to create multiple flows for every user you need to copy the file to.
If this doesn't meed your requirement, then I'm afraid that you cannot achieve this easily in Flow so far.
Test if you could use the Find files in Folder action to pick up files from one ODFB and create new files in another ODFB.
Could you give me an example of Find files in Folder please? I would like to know how it works, specifically the query to pick up files from a folder.
Thank you in advance.