using System;

using System.Text.Json;

using AutoMapper;

​

public class Program

{

    public static void Main()

    {

        var config = new MapperConfiguration(cfg =>

        {

            cfg.CreateMap<ReservationSource, ReservationDestination>()

                .ForMember(dest => dest.ReturnTravelD, opt => opt.MapFrom(src => src.ReturnTravelS))

                .ForMember(dest => dest.TowardsTravelD, opt => opt.MapFrom(src => src.TowardsTravelS));

            cfg.CreateMap<TravelS, TravelD>();

        });

        var mapper = config.CreateMapper();

        var source = new ReservationSource

        {

            ReservationNumber = "9821", 

            ReturnTravelS = new TravelS

            {

                TravelId = "1"

            }, 

            TowardsTravelS = new TravelS

            {

                TravelId = "2"

            }

        };

        var destination = mapper.Map<ReservationDestination>(source);

        Console.WriteLine(JsonSerializer.Serialize(destination));

    }

}

​

public class ReservationSource

{

    public string ReservationNumber

    {

        get;

        set;

    }

​

    public TravelS TowardsTravelS

    {

        get;

        set;

    }

​

    public TravelS ReturnTravelS

    {

        get;

        set;

    }

}

​

public class ReservationDestination

{

    public string ReservationNumber

    {

        get;

        set;

    }

​

    public TravelD TowardsTravelD

    {

        get;

        set;

    }

​

    public TravelD ReturnTravelD

    {

        get;

        set;

    }

}

​

public class TravelD

{

    public string TravelId

    {

        get;

        set;

    }

}

​

public class TravelS

{

    public string TravelId

    {

        get;

        set;

    }

}