View

xib-based

Drag NSView control to xib interface from control libraries, change control custom class to component class name of your exported.

code-based

Declare lazy load variable in the controller class and add it to the view.

import Cocoa
class ViewController: NSViewController {
    lazy var hdView: HDView = {
        let view = HDView(frame: NSRect(x: 100, y: 100, width: 100, height: 100))
        return view
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.addSubview(hdView)
    }

}