Table schema:
CREATE TABLE table_20217456_7 (rl_süd__1st_ VARCHAR, rl_südwest__1st_ VARCHAR)

Question: Who was RL Süd (1st) when FK Pirmasens was RL Südwest (1st)?
SQL: SELECT rl_süd__1st_ FROM table_20217456_7 WHERE rl_südwest__1st_ = "FK Pirmasens"