title: Angular material multi select get selected value on hide
body: <p><strong>Scenario :</strong></p>
  
  <ul>
  <li>I have a filter in angular material multi-select</li>
  </ul>
  
  <p><strong>Todo :</strong></p>
  
  <ul>
  <li><p>I want to get the selected values on hide of dropdown..</p>
  
  <blockquote>
    <p>I googled and tried to find the doc but could not found any ref to add
    hide event to miltiselect</p>
  </blockquote></li>
  </ul>