Free Text is the default selection mode when the text filter column has more than 30 values.
On the dashboard, it shows a free text entry box.
When entering a value, matches are displayed allowing you to pick one from the list. You can do so by double-clicking on it.
For Free Text with Substring default wildcard, entering Bank for this example displays values that contain Bank.
For Free Text with Prefix default wildcard, entering Bank for this example displays values that begin with Bank.
The number of options/suggestions on the drop-down will depend on the Suggestion List Max Size. Default is 10.