Nest HBox into VBox
<?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute"> <mx:VBox> <mx:Button label="Example Button 1" /> <mx:Button label="Example Button 2" /> <mx:HBox> <mx:Button label="Example Button 3" /> <mx:Button label="Example Button 4" /> </mx:HBox> </mx:VBox> </mx:Application>