In order to search on a term, phrase, or word within a free text filter, all you have to do is type in the search term, phrase, or word and click enter or return on your keyboard. You will see a blue box appear around the search value indicating that the tool recognizes this as an active search term.
To search on multiple values for the same filter, simply click enter or return after each. You can enter up to 200 terms, making sure that each is separated by its own blue box. If you want to search on more than 200 terms, you can upload a CSV file by selecting the gray picklist icon to the far right of the filter, then clicking "Add Title List."