For good search its very important that you select best keyword for searching however Select your keyword charily.
There are many title in Gbt for choose Ex : Movie , Music ... Select one of them
There are many file extension for any title , you can select each extension that you need.
With this new section of gbt you modify queries or add new query in your database. I offer you before any modify in database make backup file of your database file ( db.gbt ) . You can click on Help bottom to know more about google operators. You can add/delete/modify the queries/sites/file types
How you can make a query
There is some important keyword in query : types , here
The word here will be replaced by your keyword in searching form and the types will be replaced by your file types selected.