var win = Ti.UI.createWindow();
var btn = Ti.UI.createButton({
	title: "open"
})
win.add(btn);

btn.addEventListener("click", function() {
	createWindow();
})

function createWindow() {
	let newWin = Ti.UI.createWindow({});
	newWin.open();
	let newButton = Ti.UI.createButton({
		title: "close",
		bottom: 0
	})
	let newButton2 = Ti.UI.createButton({
		title: "new"
	})
	newWin.add([newButton, newButton2]);
	newButton.addEventListener("click", function() {
		tab1.popToRootWindow();
	});
	newButton2.addEventListener("click", function() {
		createWindow()
	});
}

var tab1 = Ti.UI.createTab({
		window: win,
		title: 'a'
	}),
	tab2 = Ti.UI.createTab({
		window: Ti.UI.createWindow(),
		title: 'b'
	}),
	tabGroup = Ti.UI.createTabGroup({
		tabs: [tab1, tab2]
	});
tabGroup.open();