MainWindow.xaml

<Window x:Class="Q412037.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
        xmlns:local="clr-namespace:Q412037"
        Title="MainWindow" Height="350" Width="525">
    <StackPanel>
        <dxg:LookUpEdit
            x:Name="lookUpEdit" Width="290" 
            PopupMinHeight="150"
            DisplayMember="LongName"
            ValueMember="ID"
            AutoPopulateColumns="False"
            ImmediatePopup="True"
            FilterCondition="Contains"
            SubstituteDisplayFilter="lookUpEdit_SubstituteDisplayFilter">
            <dxg:LookUpEdit.PopupContentTemplate>
                <ControlTemplate>
                    <dxg:GridControl Name="PART_GridControl">
                        <dxg:GridColumn FieldName="ID" Header="ID"/>
                        <dxg:GridColumn FieldName="ShortName" Header="Name"/>
                        <dxg:GridColumn FieldName="LongName" Header="Long Name"/>
                        <dxg:GridControl.View>
                            <dxg:TableView AutoWidth="True" BestFitModeOnSourceChange="AllRows"/>
                        </dxg:GridControl.View>
                    </dxg:GridControl>
                </ControlTemplate>
            </dxg:LookUpEdit.PopupContentTemplate>
        </dxg:LookUpEdit>
    </StackPanel>
</Window>