This hadith is present in our books, just quoting it from shia book “Awali al-Ali” of ibn Abi Jumhoor (p 102):
فقال النبي ص إن ابني هذاسيد و إن الله تعالي يصلح به بين فئتين عظيمتين من المسلمين
Messenger (sallalahu alaihi wa ala alihi wa sallam) said: This son of mine is chief! Allah would make a treaty by him between two big Islamic groups.
Imam Hasan made treaty with the group of Muawiyah.