The facing 3-bet filter is missing the "_p" street specifier:
holdem_hand_player_statistics.flg_p_3bet_def_opp
The database fields are listed in the
Database Schema, and the queries are in SQL, which you can find more information about at
www.PostgreSQL.org if you're interested.
The filters are being overhauled for PT4, but this manual mechanism will remain as it just isn't possible to build in every possible option that anyone may ever want - that's why we have the custom stat and report options.