for a column value in a DevExpress grid, show the name of a child

If you have a dx:ASPxGridView showing off a list of Foo and each Foo has a child Bar kept in a property called "TheBar" on Foo and TheBar has a string property called BarName...

<dx:GridViewDataComboBoxColumn FieldName="TheBar.BarName" VisibleIndex="13">
   <PropertiesComboBox ValueField="BarId" TextField="BarName"
         ValueType="System.String" DropDownStyle="DropDown" />
</dx:GridViewDataComboBoxColumn>