share files between user profiles

Having used Migration Assistant to move a file from PC to Mac, the process created a user profile where the file is now stored.

I want to share (I want to move it, really) the file with my main profile.

When I click on the destination 'Public' folder, a popup message tells me I'm not allowed to access that folder. I do note, however that the public folder, is shared, as shown in the attached screengrab.

Can you also tell me whether once transferred, the file in the destination folder will be a copy or just a shortcut in the ad hoc user profile.

Please someone tell me what's missing in the setup for me to be able to copy to that folder.

Many thanks!