@{
    var list = (ViewData[ViewData.ModelMetadata.PropertyName + "SelectList"] as MultiSelectList) ?? new MultiSelectList(new List<SelectListItem>());
    var index = 1;
}
<select class="col-xs-10 col-sm-5 edit-multiSelect MultiSelectList" id="@Html.Id("")" multiple="multiple" name="@Html.Name("")">
    @foreach (var item in list.OrderBy(o => o.Group?.Name))
    {
        if (item.Selected)
        {
            <option value="@item.Value" data-section="@item.Group?.Name" data-index="@index" selected="selected">@item.Text</option>

        }
        else
        {
            <option value="@item.Value" data-section="@item.Group?.Name" data-index="@index">@item.Text</option>
        }
        index += 1;
    }
</select>