Possibility to move an item from one site to the other (multisite)

[Alpenverein]

If you run a multisite, lets call them "Site-a" and "Site-b", it's possible to write an article in "Site-a" and show it also at "Site-b".
But it is not possible to move it from "Site-a" to "Site-b", which would be helpful if you accidentially created and edited the artical on the wrong site.
This might be a Button in the UI or a Command for the CLI.