In the Developer perspective, you can search for a resource and directly add it to the left-hand navigation (via a "Add to navigation" button that appears in the accordion header).  See screen recording below.

In what was formerly called the Administrator perspective, when you search and find a resource, clicking on the star favorites the search page with no context (query parameters are not saved as part of the favorite), and there is no way to add a favorite to a resulting resource list page since the "Add to navigation" button is not present in the accordion header.  There should be a way to add a favorite to a resulting resource list page from the Search page.  One option would be to restore the "Add to navigation" button functionality in the accordion header.  Another would be to make the resource list page's favoriting button visible on the search page (it is part of the resource list page's header).  We should consult with UX.