You can use the Quick Search options to refine your search.
To Set Quick Search Options:
Quick Search Options
| Include file names | Searches for file and folder names that begin with the search term. | 
| Include categories | Searches for categories that match the search term, and returns any files assigned to those categories. Subcategories are not included. | 
| Include contents of folders | Searches for folder names that begin with the search term and returns the contents of those folders. Subfolders are not included. |