Just type a word or words that describe the subject matter of the scene you're working on into the "Search" box and press "Enter" or click on the "Find" button.  Almost instantly a list of "hits" will come up, showing the contents of the sample.  As you scroll down this list the dialogue sample associated with the search words will be shown, along with the scene setup information, any notes about the techniques used, and the title of the source and (of course) who wrote it.  The next page shows what this looks like.