If you open system preferences > iCloud and uncheck the box of iCloud Drive a pop up window appears , showing to keep a copy of documents , and remove from the Mac .
( a ) if you had clicked on keep a copy , they will be archived in home folder that can be viewed by clicking on finder in the dock , take cursor on top menu bar > Go > Home > your user name > iCloud Drive ( Archive ) .
If you check the box of iCloud Drive once again , the admin password is required it will once again turned , the same process repeats if you sign out from iCloud https://support.apple.com/en-in/guide/mac-help/mh36825/1www.icloud.com
See this also https://discussions.apple.com/docs/DOC-13681
For another Apple ID that is different than in your Mac ( signed in system preferences > iCloud ) , you can sign a different Apple ID with its password by opening a new tab on the Mac ( use command and T keys ) and sign in with www.icloud.com and can download the desired data on the same Mac .
Note : archiving iCloud data makes a second copy of them , suppose by mistake you delete any files / documents they are deleted after 30 days from trash or you directly trash them they are gone , but can be recovered from archive folder in emergency ( use command and A keys to select them , command and C keys to copy and paste over the documents folder in the finder once again use command and V keys ) .