Example of using ContentViewController to manipulate views in macOS 10.10+ to answer http://stackoverflow.com/q/30071264/3938401
This is an example Cocoa macOS project that shows you how to use a storyboard and a ContentViewController to swap in and out views without showing a new window.
There's a Swift version by @Ruzard here: https://github.com/Ruzard/ContainerSequencedView