(swift 4/iOS 11) Just simply say for bottom:
yourView.clipsToBounds = true
yourView.layer.cornerRadius = 10
yourView.layer.maskedCorners = [.layerMaxXMaxYCorner, .layerMinXMaxYCorner]
for Up:
yourView.clipsToBounds = true
yourView.layer.cornerRadius = 10
yourView.layer.maskedCorners = [.layerMaxXMinYCorner, .layerMinXMinYCorner]
in your case:
yourView.layer.maskedCorners = [.layerMaxXMaxYCorner, .layerMinXMaxYCorner, .layerMinXMinYCorner]
Hope this help 🙂