public abstract class Entity : IHaveTrackingState
{
    public long Id { get; set; }
    [NotMapped] public TrackingState TrackingState { get; set; }
}

public class Master : Entity
{
    public string Title { get; set; }
    public ICollection<Detail> Details { get; set; }
}

public class Detail : Entity
{
    public string Title { get; set; }

    public ICollection<DetailOfDetail> Details { get; set; }
    public Master Master { get; set; }
    public long MasterId { get; set; }
}

public class DetailOfDetail : Entity
{
    public string Title { get; set; }
    public Detail Detail { get; set; }
    public long DetailId { get; set; }
}

public abstract class Model : IHaveTrackingState
{
    public long Id { get; set; }
    public TrackingState TrackingState { get; set; }
}

public class MasterModel : Model
{
    public string Title { get; set; }
    public ICollection<DetailModel> Details { get; set; }
}

public class DetailModel : Model
{
    public string Title { get; set; }
    public ICollection<DetailOfDetailModel> Details { get; set; }
}

public class DetailOfDetailModel : Model
{
    public string Title { get; set; }
}

Mapper.Initialize(expression =>
{
    expression.CreateMap<MasterModel, Master>(MemberList.None).ReverseMap();
    expression.CreateMap<DetailModel, Detail>(MemberList.None).ReverseMap();
    expression.CreateMap<DetailOfDetailModel, DetailOfDetail>(MemberList.None).ReverseMap();
});

var masterModel = new MasterModel
    {
        Title = "Master-Title",
        TrackingState = TrackingState.Added,
        Details = new List<DetailModel>
        {
            new DetailModel
            {
                Title = "Detail-Title",
                TrackingState = TrackingState.Added,
                Details = new List<DetailOfDetailModel>
                {
                    new DetailOfDetailModel
                    {
                        Title = "DetailOfDetail-Title",
                        TrackingState = TrackingState.Added,
                    }
                }
            }
        }
    };

using (var context = new ProjectDbContext())
{
    Console.WriteLine("################ Create Master and Details and DetailsOfDetail ##################");
    Print(masterModel);

    var masterEntity = Mapper.Map<Master>(masterModel);

    context.ChangeTracker.TrackGraph(
        masterEntity,
        n =>
        {
            var entity = (IHaveTrackingState) n.Entry.Entity;
            n.Entry.State = entity.TrackingState.ToEntityState();
        });

    context.SaveChanges();
}

public static class TrackingStateExtensions
{
    public static EntityState ToEntityState(this TrackingState trackingState)
    {
        switch (trackingState)
        {
            case TrackingState.Added:
                return EntityState.Added;

            case TrackingState.Modified:
                return EntityState.Modified;

            case TrackingState.Deleted:
                return EntityState.Deleted;

            case TrackingState.Unchanged:
                return EntityState.Unchanged;

            default:
                return EntityState.Unchanged;
        }
    }

    public static TrackingState ToTrackingState(this EntityState state)
    {
        switch (state)
        {
            case EntityState.Added:
                return TrackingState.Added;

            case EntityState.Modified:
                return TrackingState.Modified;

            case EntityState.Deleted:
                return TrackingState.Deleted;

            case EntityState.Unchanged:
                return TrackingState.Unchanged;

            default:
                return TrackingState.Unchanged;
        }
    }
}

using (var context = new ProjectDbContext())
{
    Console.WriteLine(
        "################ Unchanged Master and Modified Details and Deleted DetailsOfDetail ##################");
    Print(masterModel);

    var masterEntity = Mapper.Map<Master>(masterModel);

    context.ChangeTracker.TrackGraph(
        masterEntity,
        n =>
        {
            var entity = (IHaveTrackingState) n.Entry.Entity;
            n.Entry.State = entity.TrackingState.ToEntityState();
        });

    context.SaveChanges();
}

public class MasterValidator : AbstractValidator<MasterModel>
{
    public MasterValidator()
    {
        RuleFor(a => a.Title).NotEmpty();
        RuleForEach(a => a.Details).SetValidator(new DetailValidator());
    }
}

public class DetailValidator : AbstractValidator<DetailModel>
{
    public DetailValidator()
    {
        RuleFor(a => a.Title).NotEmpty();
        RuleForEach(a => a.Details).SetValidator(new DetailOfDetailValidator());
    }
}

public class DetailOfDetailValidator : AbstractValidator<DetailOfDetailModel>
{
    public DetailOfDetailValidator()
    {
        RuleFor(a => a.Title).NotEmpty();
    }
}