After the search has completed, the Quick View dropdown appears with the top three results for each document/data type. If you've typed a specific search term--like a part number--there's a good chance the exact document you want will be listed in Quick View. Simply click on the document in Quick View to open it. 

If you searched for a general term or word, chances are there are so many results returned that it's necessary to drill down in the search results to find the specific document you're seeking. In this case, use the bottom link in Quick View to "View All Results". Clicking "View All Results" will close the Quick View dropdown and open the Advanced Global Search screen which has many filters available for each document/data type. See the FAQ, "How does Advanced Global Search work?".