You need the DVD Player to play the Video_TS files. Launch DVD Player and use the
Navigate to the WD server and select the folder containing the iDVD project you want to open:
and see if that won't play for you.
Each iDVD project's Video and Audio folders should be in their own separate folder.
The above works when those fodlers are on an external HD but I have no experience on a cloud drive so you'll have to give it a try and see for yourself.