The search bar in the LibX add-on is configured to allow you to search by a variety of methods. These options are on the left side of the search bar.
If you click the little circle icon to the right of the search bar you can add another search term to your search. To the right of that you can choose where to search. The preset options are our library catalog (CatalogUSMAI), FindIt at UMCP, Worldcat UMD, and Google Scholar.
You can maximize the video below by clicking the box in the lower right corner.