Create Secondary Navigation From Structure Group

CustomNavigationProvider

 public class CustomNavigationProvider : INavigationProvider
    {
        //  #region INavigationProvider Members

        /// <summary>
        /// Gets the Navigation Model (Sitemap) for a given Localization.
        /// </summary>
        /// <param name="localization">The Localization.</param>
        /// <returns>The Navigation Model (Sitemap root Item).</returns>
        public SitemapItem GetNavigationModel(Localization localization)
        {
            using (new Tracer(localization))
            {
                string url = SiteConfiguration.LocalizeUrl("navigation.json", localization);
                // TODO TSI-110: This is a temporary measure to cache the Navigation Model per request to not retrieve and serialize 3 times per request. Comprehensive caching strategy pending
                string cacheKey = "navigation-" + url;
                HttpContext httpContext = HttpContext.Current;
                if (httpContext != null && httpContext.Items[cacheKey] != null)
                {
                    Log.Debug("Obtained Navigation Model from cache.");
                    return (SitemapItem)HttpContext.Current.Items[cacheKey];
                }

                Log.Debug("Deserializing Navigation Model from raw content URL '{0}'", url);
                DefaultProviderTmsc provider = new DefaultProviderTmsc();
                string navigationJsonString = provider.GetProperPageContent(url, localization);
                SitemapItem result = JsonConvert.DeserializeObject<SitemapItem>(navigationJsonString);

                if (httpContext != null)
                {
                    httpContext.Items[cacheKey] = result;
                }

                return result;
            }
        }

        public SitemapItem GetContextSecondaryNavigationLinks(string requestUrlPath, Localization localization)
        {
            using (new Tracer(requestUrlPath, localization))
            {
                SitemapItem sitemapItem = (SitemapItem)GetNavigationModel(localization); // Start with Sitemap root Item.
                int levels = requestUrlPath.Split('/').Length;

                SitemapItem secondaryNavigationModel = new SitemapItem();

                while (levels > 1 && sitemapItem.Items != null)
                {
                    sitemapItem =
                        sitemapItem.Items.FirstOrDefault(
                            i => requestUrlPath.StartsWith(i.Url, StringComparison.InvariantCultureIgnoreCase));
                    if (sitemapItem != null)
                    {
                        if (sitemapItem.Type != "Page")
                        {
                            secondaryNavigationModel = sitemapItem;
                        }
                        levels--;
                    }
                    else
                    {
                        break;
                    }
                }
                return secondaryNavigationModel;
            }

        }

        /// <summary>
        /// Gets Navigation Links for the top navigation menu for the given request URL path.
        /// </summary>
        /// <param name="requestUrlPath">The request URL path.</param>
        /// <param name="localization">The Localization.</param>
        /// <returns>The Navigation Links.</returns>
        public NavigationLinks GetTopNavigationLinks(string requestUrlPath, Localization localization)
        {
            using (new Tracer(requestUrlPath, localization))
            {
                NavigationLinks navigationLinks = new NavigationLinks();
                SitemapItem sitemapRoot = GetNavigationModel(localization);
                foreach (SitemapItem item in sitemapRoot.Items.Where(i => i.Visible))
                {
                    navigationLinks.Items.Add(CreateLink((item.Title == "Index") ? sitemapRoot : item));
                }
                return navigationLinks;
            }
        }

        /// <summary>
        /// Gets Navigation Links for the context navigation panel for the given request URL path.
        /// </summary>
        /// <param name="requestUrlPath">The request URL path.</param>
        /// <param name="localization">The Localization.</param>
        /// <returns>The Navigation Links.</returns>
        public NavigationLinks GetContextNavigationLinks(string requestUrlPath, Localization localization)
        {
            using (new Tracer(requestUrlPath, localization))
            {
                NavigationLinks navigationLinks = new NavigationLinks();
                SitemapItem sitemapItem = GetNavigationModel(localization); // Start with Sitemap root Item.
                int levels = requestUrlPath.Split('/').Length;
                while (levels > 1 && sitemapItem.Items != null)
                {
                    SitemapItem newParent = sitemapItem.Items.FirstOrDefault(i => i.Type == "StructureGroup" && requestUrlPath.StartsWith(i.Url, StringComparison.InvariantCultureIgnoreCase));
                    if (newParent == null)
                    {
                        break;
                    }
                    sitemapItem = newParent;
                }

                if (sitemapItem != null && sitemapItem.Items != null)
                {
                    foreach (SitemapItem item in sitemapItem.Items.Where(i => i.Visible))
                    {
                        navigationLinks.Items.Add(CreateLink(item));
                    }
                }

                return navigationLinks;
            }

        }



        /// <summary>
        /// Gets Navigation Links for the breadcrumb trail for the given request URL path.
        /// </summary>
        /// <param name="requestUrlPath">The request URL path.</param>
        /// <param name="localization">The Localization.</param>
        /// <returns>The Navigation Links.</returns>
        public NavigationLinks GetBreadcrumbNavigationLinks(string requestUrlPath, Localization localization)
        {
            using (new Tracer(requestUrlPath, localization))
            {

                NavigationLinks navigationLinks = new NavigationLinks();
                int levels = requestUrlPath.Split('/').Length;
                SitemapItem sitemapItem = (SitemapItem)GetNavigationModel(localization); // Start with Sitemap root Item.
                navigationLinks.Items.Add(CreateLink(sitemapItem));
                while (levels > 1 && sitemapItem.Items != null)
                {
                    sitemapItem =
                        sitemapItem.Items.FirstOrDefault(
                            i => requestUrlPath.StartsWith(i.Url, StringComparison.InvariantCultureIgnoreCase));
                    if (sitemapItem != null)
                    {
                        navigationLinks.Items.Add(CreateLink(sitemapItem));
                        levels--;
                    }
                    else
                    {
                        break;
                    }
                }
                return navigationLinks;
            }

        }

        protected static Link CreateLink(SitemapItem sitemapItem)
        {
            string url = sitemapItem.Url;
            if (url.StartsWith("tcm:"))
            {
                url = SiteConfiguration.LinkResolver.ResolveLink(url);
            }
            return new Link
            {
                Url = url,
                LinkText = sitemapItem.Title
            };
        }

    }

CustomNavigationsController

public class CustomNavigationsController : NavigationController
    {
        public override ActionResult Navigation(EntityModel entity, string navType, int containerSize = 0)
        {
            if (navType.Trim().ToLower() == "topmenu")
            {
                SitemapItem model = (SitemapItem)SiteConfiguration.NavigationProvider.GetNavigationModel(WebRequestContext.Localization);
                EntityModel sourceModel = (EnrichModel(entity) as EntityModel) ?? entity;
                model.XpmMetadata = sourceModel.XpmMetadata;
                model.XpmPropertyMetadata = sourceModel.XpmPropertyMetadata;

                return View(sourceModel.MvcData.ViewName, model);
            }
            else if (navType.Trim().ToLower() == "secmenu")
            {
                CustomNavigationProvider provider = new CustomNavigationProvider();
                SitemapItem model = (SitemapItem)provider.GetContextSecondaryNavigationLinks(Request.Path,WebRequestContext.Localization);
                
                EntityModel sourceModel = (EnrichModel(entity) as EntityModel) ?? entity;
                model.XpmMetadata = sourceModel.XpmMetadata;
                model.XpmPropertyMetadata = sourceModel.XpmPropertyMetadata;

                return View(sourceModel.MvcData.ViewName, model);
            }
            else
            {
                return base.Navigation(entity, navType, containerSize);
            }

        }
	}