In a number of places throughout the application you can add additional fields by clicking or by pressing CTRL+TAB once you have made an entry in the field.
If you add extra fields on a search page, the search results will return records that match any of the additional search fields.
On some search pages, after you perform a search, the search section, which contains all of the search fields, automatically minimizes. To expand this section of the page to view your search items or enter new ones, select the inverted arrow to the right of the section heading.