title: Use mat-button-toggle-group inside a mat-grid
body: <p>I have 5 buttons occupying 5 columns of a <code>mat-grid</code>. The buttons should behave as toggle buttons and all 5 should belong to a single group.<br>
  I tried enclosing the <code>mat-grid</code> with <code>mat-button-toggle-group</code>, but still isn't working.<br>
  Any help is much appreciated.</p>
  
  <p>Code : </p>
  
  <pre><code> &lt;mat-grid-list cols="11" rowHeight="40px"&gt;  
     &lt;mat-grid-tile &gt;
        &lt;label&gt;Label 1&lt;/label&gt;&lt;!-- below buttons should be a single group --&gt;
     &lt;/mat-grid-tile&gt;
     &lt;mat-grid-tile colspan='2'&gt;
            &lt;mat-button-toggle &gt;Button 1&lt;/mat-button-toggle&gt;
  
      &lt;/mat-grid-tile&gt;
        ....
       &lt;mat-grid-tile colspan='2'&gt;
            &lt;mat-button-toggle &gt;Button 5&lt;/mat-button-toggle&gt;
       &lt;/mat-gri-tile&gt;
  </code></pre>