Officially no, there is no way to hide the Private Shares from those who’s permission is set to No Access. This has been complained about once or twice in the past in other threads. Everyone who can access the My Cloud will see the Private Shares but without having a User name configured for Read Only or Full Access they will be prevented from seeing the contents of that Private Share.
Here are some past threads where the subject of hiding a Share has been discussed:
https://community.wd.com/t/feature-request-hide-share-in-explorer/149509
https://community.wd.com/t/how-to-hide-private-folder-from-other-users/156482
