This is all Barcelona's fault in the end as they couldn't stay solid from the beginning. I was pretty sure about them to qualify for next round before the group matches started. I was even thinking about whether they would manage to be the leader at the end. But they are about to visit the Europa League two times in a row now.
Barcelona is in such a position because of their own fault. To be specific, Barcelona dropped points in two matches against Inter Milan due to the poor performance of their defenders. Barcelona also had tactical problems. Barcelona's attack was inactive in the first two matches against Inter Milan and Bayern Munich. Barcelona will have to play more aggressively in the next two matches. Otherwise, they will not be able to go to the next round.