As of now Azure DNS zone migration is limited to across resource groups and subscriptions. I would recommend you post you this feature request here in this feedback section for its future availability.
You can upvote it and other features that are of interest. In general, Azure feature team would check feasibility of a feature request, triage it, prioritize against existing feature backlog, add in roadmap as appropriate and would announce and/or update the related Azure document once a feature request is addressed.
Please do not forget to "Accept the answer" wherever the information provided helps you to help others in the community.