The menu options to the right are arranged by recent and current League Seasons. Under each season are all the League Types playing in that season.
Clicking on an option will do an automatic TennisLink advanced search for you, and will display all flights and subflights within a League Type. That means all NTRP levels will be shown, so you may need to scroll down to locate the subflight or teams of specific interest to you.
The results will take a moment to display while the search is being completed. Once displayed, all links will be active, so you can drill down to view individual teams and players.