How can i make a tournament mode?

i want to make a multiplayer elimination tournament game mode, there is a tournament session created where everyone joins, then other sessions are created for each 1v1 battle and the tournament session result is stored in the game instance. after the 1v1 is over, the clients reconnect to the base tournament session by getting the stored session result form the game instance. is this possible or is there a better way to do this? also can the host of the tournament sessions connect to a 1v1 session themselves and then reconnect back to the tournament session that they hosted?