Assume a custom UIView, CustomView, that is designed with a Xib file. Inside CustomView is a UIButton, CustomButton.
ParentView is a UIView that contains CustomView.
With Storyboard, is it possible to create an auto-layout constraint that center aligns CustomButton with another button in ParentView?
No it is not possible to do what you are trying to do in storyboard. You would have to do it programatically.