Conversation so far:
What was a goal Lionel Messi broke in 2012?
On 7 March, Lionel Messi scored five times in a Champions League last 16-round match against Bayer Leverkusen, an unprecedented achievement in the history of the competition.
who did Lionel Messi play for in 2012?
Lionel Messi has spent his entire professional career with Barcelona

Question: how many goals did he score to break the record?
Self-contained rewrite: how many goals did Lionel Messi score to break the record of top goalscorer in Barcelona's history?