Current:
It occurs to me that the library and widget searches are in the wrong order. The buttons beside the widget search have to do with creating/adding to libraries (not widgets) and the selection of a widget is subordinate to the selection of a library in the IA.
The library drop is much larger than the search and I’m not sure what your testing suggests, but I search widgets MUCH more frequently than I change which libraries I have active.
My hastily done suggestion, for the sake of clarity: