public partial class ContactController : Controller
    {
        private IGroupsBusiness _groupsBusiness;
        private IContactsBusiness _contactsBusiness;

        public ContactController(IContactsBusiness contactsBusiness, IGroupsBusiness groupsBusiness)
        {
            _groupsBusiness = groupsBusiness;
            _contactsBusiness = contactsBusiness;
        }

     

        public virtual ActionResult View(int id)
        {
            var model = _contactsBusiness.Select(id);
            return View(model);
        }

        public virtual ActionResult ViewGroups(int contactId)
        {
            var model = _groupsBusiness.SelectByContactId(contactId);
            return PartialView(model);
        }
}

 @{ Html.RenderAction(MVC.Contact.ViewGroups(Model.Id)); }