title: Flutter Web : Need menu with sub menu
body: <p>How to build Menu with Submenu like shown below in image using Flutter web</p>
  
  <p><a href="https://i.stack.imgur.com/LsKv0.png" rel="noreferrer"><img src="https://i.stack.imgur.com/LsKv0.png" alt="enter image description here"></a></p>