It would be good to have the capability to both:
- Migrate a multisite subsite to a standalone instance
- Migrate a multisite subsite to another multisite
This idea was posted in UpdraftPlus - backup/restore plugin and tagged migrate, multisite on July 3, 2017 by 
hostmaster6.
Hi,
Thank you for the feedback. We’d like to see this too and it is on our internal feature list. We have done some exploration and research on how to make it happen; but currently there are quite a few things in front in the queue.
David
Any update on Migrate a multisite subsite to another multisite?
I also need the feature to migrate/restore a subsite to another installation. Are there any news since 2017?