Sure bro. Look, in the next tournament, the APERTURA, is when they decide which teams qualify to the Libertadores. The first and second place (of the regular tournament, not the playoffs) qualify as México 1 and México 2. If one of them ends up being the champion, then their place is given to the third place (of the regular tournament).
Mexico 3 is decided by another tournament, the Copa MX; the champions of the two cups of the year play against each other, and the winner qualifies to the Libertadores.
Basically:
Mexico 1 = 1st place
Mexico 2 = 2nd place
Mexico 3 = Winner of the supercopa
If one of them wins the championship, then they go to the CONCACAF CL.