Find the commit you want to revert to on bitbucket
Checkout that commit
git checkout <commit hash>
make a new branch based on that commit
git checkout -b <repair branch>
add any other later commits you want to keep (optional)
git cherry-pick <commit hash>
Switch to the broken branch
git checkout <broken branch>
Perform a hard reset on the broken branch to the commit prior to the commit you want to revert to
git reset --hard <commit hash>
Merge your fixed branch back into the reset branch
git merge <repair branch>
Push the changes back to the origin (may need to force)
git push --force origin <broken branch>