How to displays a back arrow on the home area of the action bar.

Here is the sample code. Please take a look

var win = Ti.UI.createWindow({

title : "Old Title",

navBarHidden : false

});

var actionBar;

win.addEventListener("open", function() {

if (Ti.Platform.osname === "android") {

if (!win.activity) {

Ti.API.error("Can't access action bar on a lightweight window.");

} else {

actionBar = win.activity.actionBar;

if (actionBar) {

actionBar.backgroundImage = "/bg.png";

actionBar.displayHomeAsUp = true;

actionBar.onHomeIconItemSelected = function() {

alert("Home icon clicked!");

};

}

}

}

});

win.open(); 

Check out this link as well 

- http://docs.appcelerator.com/platform/latest/#!/api/Titanium.Android.ActionBar

Hope this helps.