Not to the best of my knowledge although this is a great idea considering the number of hybrid environments we expect to see for many years to come. I suggest creating a UserVoice request for this. You can vote for it here: Aggregate Forms from multiple instances of SharePoint (e.g. Hybrid) – Customer Feedback for Nintex
This is a great idea as hybrid environments are becoming increasingly common as the Enterprise moves from SharePoint on premises to Office 365. I'm please to say that this is a feature that we are currently planning and we hope to bring it to our customers soon.
In our April 2016 release we introduced the concept of a user profile to both Nintex Mobile and Nintex Mobile Enterprise which allows a user to create a profile that will store their sign in credentials. This release only allows a profile to store one set of credentials but we hope soon to allow multiple credentials to be stored within the one profile. This would mean that a user could have both a corporate identity and a cloud identity stored in the one profile such that they could see forms from either site.