Thank you @Kiran_Vedantam , I've already gone through this tutorials. I'm sure that I'm missing a permission here. Since this user is not able to view or create a viewer preset and same time another user is able to view it under Assets->Viewer preset means , the user is missing a permission. 

Issue : when the user from author group tried to author dynamic media in page, it found that the component is not showing the viewer preset ddl. It is just showing the option "NONE". when I checked, I came to know that under Tools->Assets->viewer presets we need to create / change the state of prese...