How would teams implement phased reviews?

[Brian Kinkade]

[I'm a noob to this group so please point me in the right direction if I somehow missed the obvious]

Our company has fully switched over to reviewboard for all code reviews, but we have different processes and tools for "special" reviews such as man page changes and UI reviews.  Mainly, those changes need to be reviewed by one team and then once they approve a second team takes a look.  Think of it as an developer UI review phase and then an IE (Information Engineering) review phase. Ideally, I'd like reviewboard or tools built off of it to help automate who needs to look at what, and which phase these reviews are in.

I'm imagining something like this but I'm open to suggestions:

1. Upon review creation, an email would notify a dev UI review group. 
1. Some tool would automatically determine which dev UI review group needs to see the change
2. The dev UI reviewer on duty from that group would review
3. Upon approval (ShipIt) from the dev UI reviewer, an email would notify the IE group
4. The IE reviewer on duty would review and give the final ShipIt
5. During any point, someone could look and determine which "phase" the review is in

How do other teams go about using reviewboard for this type of phased review process?  Or, do they?

Has anyone had experience developing a process like this leveraging reviewboard?

If we need to build out extensions or webhooks tooling, where should we start?

Thanks,

Brian