What happens if aggregate is tied in Champions League?

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Tags

1. #score
2. #aggregate
3. #tiebreaking
4. #equal
5. #after
6. #goals
7. #break
8. #shootout
9. #methods
10. #penalty
11. #extra
12. #decided
13. #considered
14. #various
15. #under
16. #scored
17. #advances