USB Drive to White Light 1tb drive - PS3 cant see files


I have connected my old standard MyBook to my new MB World -

The attached USB drive is visible and I’ve mapped it to my Windows 7 PC and can browse all files etc -

My problem is that I cannot see the files (on the attached USB drive)  when I use my Play Station 3 - (I can see files in the default shared folders on the MB World ok) I just can see any files on the attached USB drive.

Please can someone help me with step by step (idiots) instructions of how to make the contents of my attached USB drive visible on my PS3 (I don’t particularly want to transfer them over to the MB world)