Let’s see how to assign content to a playlist. Remember that playlist are used to define what to display on which screen.
First, go to the section Playlists and double-click on the list that you want to add content to.
You will arrive at this screen:

Next, you can drag-and-drop content from one of the folders in the Library (located on the right side of the screen) into your playlist.

You can drag and drop multiple files and folders into the playlist.

ATTENTION:
Remember to save all your modifications by clicking the « Save » button located on the top of the page.