@starriski The Mac OS also has symbolic link. What symbolic link does is put an invisible file in the source folder. When the OS (operating system) finds this invisible file it redirects to where the folder really is. 2 problems - 1 - someone deletes the source folder and breaks the link. 2 - usb drives get reassigned when certain conditions exist and that will break the link. When a computer boots it will assign drive designations to usb devices as they are discovered. If something changes the order of discovery at boot your usb device gets a different designation then it had before. Symbolic link works but is not the best solution...
A video isn't really the best way to learn how to create a symlink. You can read these instructions which involve copying/pasting and editing to suit your setup - https://bluebellflora.com/saving-your-sims-4-folder-to-an-external-drive/
The assigned drives and problems unplugging and plugging in drives that @roberta591 refers to is only relevant to Windows, not macOS. There are also no invisible files or folders. After successfully creating a symlink to point to the external drive you will have a folder called Electronic Arts in the Documents folder on your Mac but it will be an alias with a little arrow in the corner showing this.
