If there is a tie in points when ( league champions ) who classified?

[Pedro Rosario]

Good morning ,
Let's see, maybe my naive question paresca but something strange is going on in Champions League . I just lose a game one 1-0 . I was leading my group of but have dropped to second place. With the ex - runner , now leading , we are tied in points . Both have 12 points but I have 21 goals for and 6 goals in contra.Él , meanwhile , has 12 points and 14 goals for and 5 against .
Later plays the third (most likely win because the team that will play has not won a single game ) that has 9 points and 11 goals for and 7 against. What will happen if , as I suppose will happen , wins the third? There will be a three-way tie at the top to 12 points and what those who classified?
I thought this was defined by goal difference ( in such a situation I would go first because I have 21 goals for and only 6 against : 21-6 = 15 ) but it seems not.
I await answers.
Thank you.

[July Fourth]

Head2Head records now in CL for teams level on points.

[Buffs Mad]

If two or more teams are equal on points on completion of the group matches, the following criteria are applied to determine the rankings (in descending order):
a) higher number of points obtained in the group matches played among the teams in question;
b) superior goal difference from the group matches played among the teams in question;
c) higher number of goals scored in the group matches played among the teams in question;
d) higher number of goals scored away from home in the group matches played among the teams in question;
e) if, after having applied criteria a) to d), two teams still have an equal ranking, criteria a) to d) are reapplied to determine the final ranking of the
two teams. If this procedure does not lead to a decision, criteria f) to g)
apply;
f) superior goal difference from all group matches played;
g) higher number of goals scored fr om all group matches played

bleh'til10.

[Pedro Rosario]

bleh'til10.

With the team now in first place twice jugé, local I beat him 2-1 and Away and he just won 1-0.
With the one third jugé twice in their stadium lost 2-1 and locally (in my stadium) won 3-1.
How will this be?