Papers searches databases like PubMed and Google Scholar to intelligently find papers that might be of interest to you based on the papers you already have in your library as well as your recent activity.
You can select how far back your recommendations go by changing the time period in the drop-down box at the top of the page. You can also get recommendations on your personal library or any shared libraries that you have created.
If you do not see any recommendations in Papers, you may not have enough articles in your library
Add more articles by dragging and dropping PDFs directly into your library, or clicking the “Add” button at the top of the library window.