ViewController.swift

 import Cocoa

class ViewController: NSViewController , NSWindowDelegate {
    @IBOutlet weak var menuButton: NSButton!
    @objc func rightClick(_ sender:ClickRecognizer){
        self.selectData = sender.data
        let theMenu = popupMenuForValue(data:sender.data)
        NSMenu.popUpContextMenu(theMenu, with:NSApp.currentEvent!, for: sender.view! )
    }
    override func viewDidLoad() {
        let ges = ClickRecognizer()
        ges.target = self
        ges.data = "u07500499"
        ges.buttonMask = 0x2
        ges.numberOfClicksRequired = 1
        ges.action = #selector(rightClick(_:))
        menuButton.addGestureRecognizer(ges)
    }
}

ClickRecognizer

 import Cocoa

class ClickRecognizer: NSClickGestureRecognizer {
    var data:String = ""
}