title: Binding two properties of object in DataTamplate
body: <p>I have GridControl (Devexpress) with ItemsSource="{Binding Flow}". I implemented grouping by TagRange column. I want to change GroupValue.</p>
  
  <pre><code>&lt;dxg:GridColumn Header="Tag Range" Binding="{Binding Path=TagRange}" GroupIndex="0" &gt;
      &lt;dxg:GridColumn.GroupValueTemplate&gt;
          &lt;DataTemplate&gt;
              &lt;TextBlock Text="{Binding Value}"/&gt;
          &lt;/DataTemplate&gt;
      &lt;/dxg:GridColumn.GroupValueTemplate&gt;
  &lt;/dxg:GridColumn&gt;
  </code></pre>
  
  <p>The text of TextBlock equals TagRange property. How can I bind TextBlock Text property as <code>Name + " " +  TagRange</code>. </p>
  
  <p>Flow class:</p>
  
  <pre><code>public class Flow
  {
      public string Name{ get; set; }
      public string TagRange { get; set; }
      ...
  }
  </code></pre>