However, the closest you’ll get is through Stringify. They have a section of their app stringify controls. Kinda like a dashboard sorta. You can see all of your “stuff” from there and control it. Not very configurable and still in beta I believe.
Alternative is to put together your own “dashboard” that would interface with all of your separate systems. Easier said than done though.
Not sure what additional capabilities you get through Nest, maybe they have something. Otherwise a lot of people use a hub like SmartThings or Wink or home grown like Home Automation or OpenHAB to integrate and centralize their stuff. And with SmartThings you get a bonus of this happy crowd!