Today I learned that in Git 2.36, the --remerge-diff option was added to git show. This effectively lets you view any merge conflicts that occurred during a merge commit and how they were resolved.

So for instance, git show --remerge-diff <commit-message-id> would show something like:

terminal screenshot of git show output

Under the hood, it recreates the merge with the conflicts and diffs it with the merge commit so the conflict markers are shown in red since the merge commit removes the conflict markers during resolution.