<dx:ASPxGridView ID="grid" runat="server" AutoGenerateColumns="False" KeyFieldName="CustomerID" >
    <Columns>
        <dx:GridViewDataTextColumn FieldName="Country" VisibleIndex="0">
            <Settings AllowGroup="True" />
        </dx:GridViewDataTextColumn>
        <%--...--%>
    </Columns>
    <Settings ShowGroupPanel="true" />
    <SettingsBehavior AllowGroup="false" />
</dx:ASPxGridView>

<dx:ASPxGridView ID="grid" runat="server">
    <%--...--%>
    <Settings ShowGroupPanel="true" ShowGroupedColumns="true"/>
</dx:ASPxGridView>

<dx:ASPxGridView ID="grid" ClientInstanceName="grid" runat="server" KeyFieldName="OrderID" 
    AutoGenerateColumns="False">
    <Columns>
        <%--...--%>
        <dx:GridViewDataDateColumn FieldName="OrderDate" GroupIndex="0">
            <Settings GroupInterval="DateYear" />
        </dx:GridViewDataDateColumn>
    </Columns>
    <Settings ShowGroupPanel="True" />
</dx:ASPxGridView>

<dx:ASPxGridView ID="grid" runat="server" KeyFieldName="ProductID" AutoGenerateColumns="false"
    OnCustomColumnGroup="grid_CustomColumnGroup"
    OnCustomGroupDisplayText="grid_CustomGroupDisplayText">
    <GroupSummary>
        <dx:ASPxSummaryItem SummaryType="Count" />
    </GroupSummary>
    <Settings ShowGroupedColumns="True" ShowGroupPanel="True" />
    <Columns>
        <%--...--%>
        <dx:GridViewDataTextColumn FieldName="UnitPrice" VisibleIndex="2" GroupIndex="0" SortIndex="0"
            SortOrder="Ascending">
            <%--...--%>
        </dx:GridViewDataTextColumn>
</dx:ASPxGridView>

protected void grid_CustomColumnGroup(object sender, DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs e) {
    if(e.Column.FieldName == "UnitPrice") {
        int res = 0;
        double x = Math.Floor(Convert.ToDouble(e.Value1) / 10);
        double y = Math.Floor(Convert.ToDouble(e.Value2) / 10);
        res = Comparer.Default.Compare(x, y);
        if(res < 0) res = -1;
        else if(res > 0) res = 1;
        if(res == 0 || (x > 9 && y > 9)) res = 0;
        e.Result = res;
        e.Handled = true;
    }
}

protected void grid_CustomGroupDisplayText(object sender, DevExpress.Web.ASPxGridView.ASPxGridViewColumnDisplayTextEventArgs e) {
    if(e.Column.FieldName == "UnitPrice") {
        double d = Math.Floor(Convert.ToDouble(e.Value) / 10);
        string displayText = string.Format("{0:c} - {1:c} ", d * 10, ((d + 1) * 10)-0.01);
        if(d > 9) displayText = string.Format(">= {0:c} ", 100);
        e.DisplayText = displayText;
    }
}

Protected Sub grid_CustomColumnGroup(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs)
    If e.Column.FieldName = "UnitPrice" Then
        Dim res As Integer = 0
        Dim x As Double = Math.Floor(Convert.ToDouble(e.Value1) / 10)
        Dim y As Double = Math.Floor(Convert.ToDouble(e.Value2) / 10)
        res = Comparer.[Default].Compare(x, y)

        If res < 0 Then
            res = -1
        ElseIf res > 0 Then
            res = 1
        End If

        If res = 0 OrElse (x > 9 AndAlso y > 9) Then res = 0
        e.Result = res
        e.Handled = True
    End If
End Sub

Protected Sub grid_CustomGroupDisplayText(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.ASPxGridViewColumnDisplayTextEventArgs)
    If e.Column.FieldName = "UnitPrice" Then
        Dim d As Double = Math.Floor(Convert.ToDouble(e.Value) / 10)
        Dim displayText As String = String.Format("{0:c} - {1:c} ", d * 10, (d + 1) * 10)
        If d > 9 Then displayText = String.Format(">= {0:c} ", 100)
        e.DisplayText = displayText
    End If
End Sub

<dx:ASPxGridView ID="Grid" runat="server" AutoGenerateColumns="false">
    <Columns>
        <dx:GridViewDataColumn FieldName="Country" GroupIndex="0" />
        <dx:GridViewDataColumn FieldName="City" GroupIndex="1" />
        <%--...--%>
    </Columns>
    <Settings ShowGroupPanel="true" GroupFormatForMergedGroupRow="{0} : {1}"
        GroupFormatForMergedGroup="{0} - {1}" />
    <SettingsBehavior MergeGroupsMode="Always" AutoExpandAllGroups="true" />
    <GroupSummary>
        <dx:ASPxSummaryItem SummaryType="Count" FieldName="City" />
    </GroupSummary>
</dx:ASPxGridView>

<dx:ASPxGridView ID="Grid" ClientInstanceName="grid" runat="server" KeyFieldName="CustomerID"
    AutoGenerateColumns="false">
    <Columns>
        <%--..--%>
        <dx:GridViewDataColumn FieldName="Country" GroupIndex="0" />
    </Columns>
    <Settings ShowGroupPanel="True" VerticalScrollBarMode="Visible" VerticalScrollableHeight="300" />
    <SettingsBehavior AllowFixedGroups="true" />
    <Images>
        <FixedGroupRow Url="custom.png" />
    </Images>
</dx:ASPxGridView>

<dx:ASPxGridView ID="ASPxGridView1" runat="server" ClientInstanceName="grid" AutoGenerateColumns="False">
    <Settings ShowGroupButtons="False" ShowGroupPanel="True" />
    <Columns>
        <%--...--%>
    </Columns>
    <Templates>
        <GroupRowContent>
            <dx:ASPxCheckBox ID="ASPxCheckBox1" runat="server" OnInit="ASPxCheckBox1_Init" />
            <%# Container.GroupText + Container.KeyValue%>
        </GroupRowContent>
    </Templates>
</dx:ASPxGridView>

function ExpandCollapse(sender, index) {
    if (sender.GetChecked())
        grid.ExpandRow(index);
    else
        grid.CollapseRow(index);
}

protected void ASPxCheckBox1_Init(object sender, EventArgs e) {
    ASPxCheckBox cb = sender as ASPxCheckBox;
    GridViewGroupRowTemplateContainer container = cb.NamingContainer as GridViewGroupRowTemplateContainer;
    if (ASPxGridView1.IsRowExpanded(container.VisibleIndex))
        cb.Checked = true;
    cb.ClientSideEvents.CheckedChanged = string.Format("function (s, e) {{ ExpandCollapse(s, {0}); }}", container.VisibleIndex);
}

Protected Sub ASPxCheckBox1_Init(ByVal sender As Object, ByVal e As EventArgs)
    Dim cb As ASPxCheckBox = TryCast(sender, ASPxCheckBox)
    Dim container As GridViewGroupRowTemplateContainer = TryCast(cb.NamingContainer, GridViewGroupRowTemplateContainer)
    If ASPxGridView1.IsRowExpanded(container.VisibleIndex) Then
        cb.Checked = True
    End If
    cb.ClientSideEvents.CheckedChanged = String.Format("function (s, e) {{ ExpandCollapse(s, {0}); }}", container.VisibleIndex)
End Sub