iMac and connected external displays, all as monitors for MacBook Pro? Say I had an iMac (assume newest models) with 2 external displays (USB-C/Thunderbolt 3?) in my office. If I bring my (assume latest) MacBook Pro into the office and would like to use it rather than the iMac, could I connect the MacBook Pro to the iMac and then use the iMac and the 2 displays connected to the iMac as monitors for the MacBook Pro? 

If so, what would I need to do to accomplish this? 

Update: (I realized I didn't clearly state my goal)

Goal: I would like to have a desktop station in the office, but a laptop for when I'm out and about. If I was working on something on the laptop and don't feel like waiting/causing some sort of syncing between the laptop and desktop, i'd like to just use the laptop as the computer and the displays for more screen real estate. (Usually, I would just use the iMac in the office and the laptop when i'm not in the office)

Update 2: Perhaps a KVM switch is the way to go? Maybe they don't yet exist for thunderbolt3, but maybe this would be the best way? Have 2 monitors that go through a KVM to get to the iMac, but could also get to my laptop this way?
Short answer:  No, this can't be done.

At the very minimum you would need to set your iMac into "Target Display Mode."  The last iMac that will support this is the Mid 2014.



Now, if you happen to have a compatible iMac (not the "newest model" you referred to), it still wouldn't work.  Target display mode turns your iMac display into an external monitor for your compatible MacBook with a Thunderbolt port.  It doesn't turn it into a "thunderbolt hub."

I am assuming you don't want to use the iMac and instead just use your MacBook and your goal is to get three monitors going...  I suggest just getting a third monitor and hooking that up to your MBP and bequeathing your latest iMac to a worthy coworker.  I am a huge proponent of finding the simplest solution and not layer it with complexity.