What government consisted of two kings and three groups of elected citizens?

The government you are referring to is that of ancient Sparta. Sparta was unique in its dual kingship, where two hereditary kings ruled simultaneously, often from different royal families. Additionally, the Spartan political system included three main groups of citizens: the assembly (Apella), the council of elders (Gerousia), and the ephors, who were elected officials responsible for overseeing various aspects of governance. This structure aimed to balance power and maintain stability within the city-state.