Can help you explain more clearly through the following analysis:
Situation 1. If Real Madrid and Barcelona share points: Needless to say! Real Madrid will win the championship with two encounters, one win and one draw this season.
Situation 2. If Real Madrid and Seville score the same point, Seville will win the championship, because they win 2-0 at home and lose 2-3 at home, which has many advantages in scoring away goals.
Situation 3. If Barcelona and Seville score goals, Barcelona will win the championship, because it has an advantage in the total score by winning Seville 3-0 at home and losing to Seville 2-0 away.
Situation 4. That is to say, if the points of Real Madrid, Barcelona and Seville are the same, in fact, we can see that the three teams are in the group stage, that is, Real Madrid has 2 wins/KOOC-0/draw/KOOC-0/negative, Barcelona/KOOC-0/win/KOOC-0/draw and Seville has 2 wins and 2 losses. Real Madrid won the championship, of course.