Which prayer has four Tashahhuds?

The fundamental principle in prayer is to have one or two tashahhuds. What you asked about occurs to a latecomer (al-masbuq) if he joins the Imam during the first tashahhud of the Maghrib prayer. If he completes the third rak'ah with the Imam, the latecomer would have performed two tashahhuds. Two rak'ahs would remain for him; he would sit for the middle tashahhud (for him) after the first of them, and the final tashahhud would remain for him in the third rak'ah. Thus, he would have performed four tashahhuds.