when testing you can add flag --dry-run Do a trial run with no permanent changes. Use this to see what rclone would do without actually doing it. Useful when setting up the sync command which deletes files in the destination
I read the documentation from rclone Onedrive and found just i wanted, the solution is change the path to folder root account like so: remote:directory/subdirectory
ex:
rclone --vfs-cache-mode writes mount onedrive:/folderA/folderB/ ~/onedrive