Use WithDataSeparator’s property to add GroupBy function on the listview.

Code:

        protected void Page_Load(object sender, EventArgs e)
        {
            Control control = ControlHelper.GetControlById(mbPage1, "lv");
            if (control is ListView)
            {
                ListView lv = control as ListView;
                List<Car> cars = CarDataAccess.GetCars();
                //you've to order your list
                var q = from c in cars
                        orderby c.Country
                        select c;
                lv.DataSource = q.ToList();
                lv.DataBind();
            }
        }

    <mob:MobilePage ID="mbPage1" runat="server">
        <Header>
            <h1>Separator List View</h1>
        </Header>
        <Content>
            <mob:ListView ID="lv" runat="server" WithDataSeparator="true" SeparatorProperty="Country">
                <ItemTemplate>  
                    <mob:Link ID="link1" Text="<%# ((Car)Container.DataItem).Name %>" Url="#" runat="server"></mob:Link>
                </ItemTemplate>
            </mob:ListView>
        </Content>
        <Footer>
            <h1>Footer</h1>
        </Footer>
    </mob:MobilePage>

Result: