title: How to group RadioButton from different LinearLayouts?
body: <p>I was wondering if is possible to group each single <code>RadioButton</code> in a unique <code>RadioGroup</code>
  maintaining the same structure. My structure look like this:</p>
  
  <ul>
  <li>LinearLayout_main
  <ul>
  <li>LinearLayout_1
  <ul>
  <li>RadioButton1</li>
  </ul></li>
  <li>LinearLayout_2
  <ul>
  <li>RadioButton2</li>
  </ul></li>
  <li>LinearLayout_3
  <ul>
  <li>RadioButton3 </li>
  </ul></li>
  </ul></li>
  </ul>
  
  <p>As you can see, now each <code>RadioButton</code> is a child of different <code>LinearLayout</code>. I tried using the structure below, but it doesn't work:</p>
  
  <ul>
  <li>Radiogroup
  <ul>
  <li>LinearLayout_main
  <ul>
  <li>LinearLayout_1
  <ul>
  <li>RadioButton1</li>
  </ul></li>
  <li>LinearLayout_2
  <ul>
  <li>RadioButton2</li>
  </ul></li>
  <li>LinearLayout_3
  <ul>
  <li>RadioButton3 </li>
  </ul></li>
  </ul></li>
  </ul></li>
  </ul>