Save the data ..selected value tree view in MVC

public ActionResult Index()
    {
        List<SubLIst> nodes = new List<SubLIst>();
    dbEntities entities = new dbEntities();

        //Loop and add the Parent Nodes.
        foreach (tblManual type in entities.tblManualLists)
        {
            nodes.Add(new SubLIst { id = type.ManualId.ToString(), parent = "#", text = type.Code });
        }

        //Loop and add the Child Nodes.
        foreach (tblSubManual subType in entities.tblSubManuals)
        {
            nodes.Add(new SubLIst { id = subType.ManualId.ToString() + "-" + subType.SubManualId.ToString(), parent = subType.ManualId.ToString(), text = subType.Code });
        }

        //Serialize to JSON string.
        ViewBag.Json = (new JavaScriptSerializer()).Serialize(nodes);
        return View();
    }

    [HttpPost]
    public ActionResult Index(string selectedItems, tblDocument employee)
    {

        if (ModelState.IsValid)
        {
            List<SubLIst> items = (new JavaScriptSerializer()).Deserialize<List<SubLIst>>(selectedItems);
            employee.ModifiedDate = DateTime.Now;

            dc.tblDocuments.Add(employee);
            dc.SaveChanges();
            return RedirectToAction("Index");
        }
        return Json(new { success = true }, JsonRequestBehavior.AllowGet);
    }
}