To which foundation of governance in Islam does the Hadith: "No people ever consulted together, except that they were guided to the most righteous of their affairs" refer?

What the questioner mentioned is not a prophetic hadith elevated to the Prophet, peace be upon him, but rather a discontinued narration (athar maqtu') from Al-Hasan Al-Basri, reported by Ibn Abi Shaybah, Al-Bukhari in Al-Adab Al-Mufrad, and others. The basis of this narration is the principle of consultation (shura) in Islam. Allah Almighty said: "And their affair is [determined by] consultation among themselves," and He said: "And consult them in the matter."