Any Share that has the Dashboard option “Media Serving” activated (set to On) will have its media cataloged and made available by the Twonky Media Server. First step is to ensure only those Shares that you want to used by Twonky have the Media Serving option set to On. Note that any media files in the Public Share will be cataloged by Twonky as there is no way currently to disable Media Serving (at least in the v4.x firmware) on the Public Share. the solution is to move media files that you do not want to be cataloged by Twonky out of the Public Share into a another Share that has Media Serving turned off.
If you have not already done so you may want to read through the following thread which has some good information on how to use the Twonky Media Server on the My Cloud.
https://community.wd.com/t/faq-twonky-dlna-media-server-setup-use/95373
