How to change the "Source Term" or owning Group for a reused term in the new Termstore admin

In the SharePoint term store, a term can be reused in another term group, so that changes made in one term are automatically reflected in the reused one.  In the old Term Store admin, you could very easily change the "owning group" or "source" by selecting the term in the group that owns it and under "Member of" clicking the radio button of the Term group you wanted to be the "owning group".
However, in the new term store admin, this "Member of" section isn't obvious and I can't find how to change the "source term".  Does anyone know where this option is in the new term store admin?  I've searched, but as this is a fairly recent change I can't find any help.