You will need two new columns like this:
cnt_steal_call_fold_to_cbet =
sum(if[ holdem_hand_player_statistics.flg_blind_def_opp AND lookup_actions_p.action='C' AND holdem_hand_player_statistics.enum_f_cbet_action='F', 1, 0])
cnt_steal_call_face_cbet =
sum(if[ holdem_hand_player_statistics.flg_blind_def_opp AND lookup_actions_p.action='C' AND holdem_hand_player_statistics.flg_f_cbet_def_opp, 1, 0])
And then a new stat to display the result, with this Value Expression:
(cnt_steal_call_fold_to_cbet / cnt_steal_call_face_cbet) * 100
See the
Tutorial - Custom Reports and Statistics for a walkthrough of building a stat using these expressions.