Using Entity Framework 6 to implement nested TPH on 2 different discriminator fields

Question

Using Entity Framework 6 to implement nested TPH on 2 different discriminator fields

I work with EF6 by first switching from edmx to Code. I did the reverse engineering from an existing DB, and I am tring to reproduce the model I had before, with a nested TPH made in a table called "Contacts", which has two different fields "Type" and "Subtype" respectively as the first , and the first discriminator of the second level.

I would like to have something like this:

Contact
    Model (Type = 1)
        BookingModel (SubType = 1)
        ScoutingModel (Subtype = 2)
    Customer (Type = 2)
        Agency (SubType = 3)
        Client (Subtype = 4)
        Service (Subtype = 5)

I encoded the Contact, Model, and Customer classes as Abstract and BookingModel, ScoutingModel, Agency, Client, Service as Concrete without including the Type and Subtype fields, as they are discriminators.

Here is the display code:

public virtual DbSet<Contact> Contacts { get; set; }


    modelBuilder.Entity<Contact>()
            .Map<Model>(e => e.Requires("Type").HasValue((byte)ContactTypeEnum.Model))
            .Map<Customer>(e => e.Requires("Type").HasValue((byte)ContactTypeEnum.Customer));

            modelBuilder.Entity<Customer>()
                .Map<Agency>(e => {
                    e.Requires("Type").HasValue((byte)ContactTypeEnum.Customer);
                    e.Requires("SubType").HasValue((byte)CustomerTypeEnum.Agency);
                })
                .Map<Client>(e => {
                    e.Requires("Type").HasValue((byte)ContactTypeEnum.Customer);
                    e.Requires("SubType").HasValue((byte)CustomerTypeEnum.Client);
                })
                .Map<Service>(e => {
                    e.Requires("Type").HasValue((byte)ContactTypeEnum.Customer);
                    e.Requires("SubType").HasValue((byte)CustomerTypeEnum.Service);
                });

            modelBuilder.Entity<Model>()
                .Map<BookingModel>(e => {
                    e.Requires("Type").HasValue((byte)ContactTypeEnum.Model);
                    e.Requires("SubType").HasValue((byte)ModelTypeEnum.Booking);
                })
                .Map<ScoutingModel>(e => {
                    e.Requires("Type").HasValue((byte)ContactTypeEnum.Model);
                    e.Requires("SubType").HasValue((byte)ModelTypeEnum.Scouting);
                });