The Gerrit documentation at
https://gerrit-review.googlesource.com/Documentation/user-upload.html#push_options lists the various command line options when you push to Gerrit. Example:
git push origin HEAD:refs/for/experimental%topic=driver/i42
However, the documentation is not explicit on how to specify multiple options on the same push. It looks like you just comma-separate them, but can someone confirm that for definite? I''ll update the documentation when I have a confirmed answer.
Thanks
Matthew