It will be great if the existing ‘Bookshelf’ or ‘Magazine Archive’ apps can support grouping by theme or topic. Then, if you have 100 publications, users can filter by topic or year for easy access!
Thanks!
Hi there, @user14366 
You’re referring to the File Embed widget, right? If so we already have this idea on the Wishlist and you can upvote it here - Option for organizing files by folder and also downloading an entire folder of files.
However, if I misunderstood you, please describe your idea in more detail 