Click on a manager's row to expand his/her live team and see which players he/she has that you don't.
Select one from your leagues:
To find your leagues in the dropdown menu, enter your FPL id in the rank page.
To find a league id instead, extract it from the url of the league https://fantasy.premierleague.com/a/leagues/standings/league_id/classic
Your team will be expanded by default.
Table will show a maximum of 200 teams in the league.