When List Fields terminates, it will save all changes done to the Field List Area. All column grouping, sorting, reordering and filtering will be preserved.
When you exit List Fields for the first time, List Fields will ask you where to store the so-called layout files. You will see this dialog box:
List Fields has by default chosen your personal directory. You can select any other directory, and List Fields will remember the directory. You can also change the layout directory at any time from the Field List Area Preferences.