Multiplayer: level to load when sessions disconnected / or stay in level

Hi guys,

Multiplayer game, listen server, the game on the main map ends. I would like to have the option to all players to either return to the main menu, or go to a new level (both single-player, no mp session should stay alive)

If server leaves the map, the others will follow, and if the session is destroyed, everyone automatically returns to the default map, before making their choice.

Any idea how to override this behaviour?