You will need to make a new pair of columns to count the actions and opportunities for that situation, like this:
(these are based on the existing column "cnt_f_2bet_def_action_call" with additions for folding to, or facing, a turn bet)
cnt_f_2bet_def_action_call_t_fold_to_bet =
sum(if[cash_hand_player_statistics.flg_f_3bet_opp AND ((cash_hand_player_statistics.amt_f_bet_facing = 0 AND lookup_actions_f.action SIMILAR TO '(C|XC|BC)%') OR (cash_hand_player_statistics.amt_f_bet_facing > 0 AND lookup_actions_f.action SIMILAR TO '(XCC|CC)%')) AND cash_hand_player_statistics.amt_t_bet_facing > 0 AND lookup_actions_f.action SIMILAR TO '(F|XF)%', 1, 0])
cnt_f_2bet_def_action_call_t_face_bet =
sum(if[cash_hand_player_statistics.flg_f_3bet_opp AND ((cash_hand_player_statistics.amt_f_bet_facing = 0 AND lookup_actions_f.action SIMILAR TO '(C|XC|BC)%') OR (cash_hand_player_statistics.amt_f_bet_facing > 0 AND lookup_actions_f.action SIMILAR TO '(XCC|CC)%')) AND cash_hand_player_statistics.amt_t_bet_facing > 0, 1, 0])
Then the new stat is:
(cnt_f_2bet_def_action_call_t_fold_to_bet / cnt_f_2bet_def_action_call_t_face_bet) * 100
I have built and attached the stat for you.
If you want more information on how to work with custom stats check out the
Tutorial: Custom Reports and Statistics - this was written for PT3 so the layout and details are a little different, but the general structure of stats works in the same way.