title: ExtJS menu group, how to deselect with a remote button
body: <p>I have several nested menu radio groups and I was wondering how to uncheck the nested menu groups from the parent menu?</p>
  
  <p>For example, I have a Ext.menu.Menu object with an item added that has a menu of another Ext.menu.Menu object. Each of these are in separate groups. I want to be able to click on another button to uncheck both of those groups.</p>
  
  <p>The scenario I have is that I have these nested options available and a deselect button that I want to reset the options.</p>
  
  <p>I am using ExtJS version 3.3.1.</p>
  
  <p>The options are dynamically generated and multiple items share the same group. They are grouped by nested depth.</p>
  
  <p>Example Menu:
  None
  Test > Still Testing > More Testing
  Test Again > Continue Testing
  Another Test</p>
  
  <p>so None, Test, Test Again, and Another Test are in the group "level1"
  Still Testing, Continue Testing are in the group "level2"
  More Testing is in the group "level3".</p>
  
  <p>I want the None button to uncheck level 2 and level 3. I am fine with it becoming checked for the level1 group.</p>