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 ) .
Again check the box of iCloud Drive , the files will be stored in iCloud .
When Mac is not connected to internet , the files are still saved in home folder > your user name > iCloud Drive ( Archive ) .