NotificationConfigurationViewModel.cs

namespace DynamicDataGroupingSample
{
    public class NotificationConfigurationViewModel : ReactiveObjectEx 
    {
        public NotificationConfigurationViewModel()
        {
            _notificationConfigurationsSourceCache.AddOrUpdate(new List<NotificationConfiguration>()
            {
                new NotificationConfiguration("Information", 0,"Development", 0,false, false, true, false),
                new NotificationConfiguration("Status Changed", 1,"Administration", 1, false, true, false, false),
                new NotificationConfiguration("Error", 3,"Development", 0, false, true, false, false),
                new NotificationConfiguration("New Report", 4,"Administration", 1, false, false, false, false),
                new NotificationConfiguration("Warning", 1,"Development", 0, false, true, false, false),
                new NotificationConfiguration("Security Update", 2, "Administration", 1, false, false, true, true),
                new NotificationConfiguration("Verbose", 2, "Development", 0, false, false, false, false),
                new NotificationConfiguration("Policy Update", 3, "Administration", 1, false, false, false, false)
            });
           
            var notificationConfigurationItemChanges = _notificationConfigurationsSourceCache.Connect()
                                                                                             .RefCount();
                                                                                             
            notificationConfigurationItemChanges
                        .Sort(SortExpressionComparer<NotificationConfiguration>.Ascending(a => a.GroupOrder))
                        .Group(x => x.GroupName)
                        .Transform(g => new ObservableGroupedCollection<string, NotificationConfiguration, string>(g, null, Observable.Return<IComparer<NotificationConfiguration>>(SortExpressionComparer<NotificationConfiguration>.Ascending(a => a.Order))))
                        .Bind(out _groups)
                        .DisposeMany()
                        .Subscribe()
                        .DisposeWith(Subscriptions);
        }

        public ReadOnlyObservableCollection<ObservableGroupedCollection<string, NotificationConfiguration, string>> NotificationGroups => _groups;

        private readonly ReadOnlyObservableCollection<ObservableGroupedCollection<string, NotificationConfiguration, string>> _groups;

        private SourceCache<NotificationConfiguration, string> _notificationConfigurationsSourceCache = new SourceCache<NotificationConfiguration, string>(x => x.Name);
    }
}