Hybrid routing enhancement - group sequence for Parallel flows

Hi there! 

It would be great to enhance the hybrid routing functionality to support defining a signing sequence for a sub-group when the main flow is set to "parallel". This would support scenarios where certain involved parties require a hierarchy of signing to be in place (example, Person 1 approves, Person 2 & 3 sign). Right now this can only be solved by pushing in a sequence for all involved parties / recipients; which can lead to long delays when multiple parties are involved. 

Is possible with the current functionality, and if not, something that is on the radar of future improvements? 

Attached a sample mockup with the intent.