I set up our WD My Cloud from our PC and set up two users. i used one account to set it up and a second accout. Now from this machine I can see the files for the first user but not the second even though they both have password requirement.
in windows you can only connect as 1 user at a time to another device
so if user1 has share1 and user2 has share2 you will need to add read or full access on share2 for user1. then user1 can see both
Unless you have two accounts on the windows box… Each windows user can access a unique set of shares.