exactly! This was possible with the sonar.branch.target property.
Now there’s only the way via web api or Sonarqube web ui, but only for branches that already exist
(i.e. the problem of @markluebbehuesen in this thread).
When using pull requests or one setting for all branches, see workaround here
all is fine, but there are many projects that don’t use PRs and there are special cases where one
general reference branch for all branches is not sufficient.