I have a large collection of files that are used by a nonprofit. The nonprofit now has a Google for Nonprofits account and I wanted to move the files that I own to that nonprofit account of which I’m an admin. I logged into the G4N account and created a new folder called Test. I shared that folder with my personal account.
I then logged into the personal account and navigated to a folder that contained a test file. I selected the file and clicked on “Move to”, navigated up to “Shared with me” (by clicking on the left arrow to reach the top folder level), then selecting the new folder called Test and clicked on “Move”. The test file was moved to that folder. Permission will need to be reset for the copied files.