using System;

using System.Collections.Generic;

using AutoMapper;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        var config = new MapperConfiguration(cfg =>

        {

            cfg.CreateMap<Customer, CustomerDto>();

​

            cfg.CreateMap<SomeType, SomeTypeDto>()

                .ForMember(dest => dest.SomeValues, opt => opt.MapFrom(src => src.Customers));

        });

        IMapper mapper = config.CreateMapper();

        var someType = new SomeType 

        { 

            Id = 1, 

            Customers = new List<Customer> 

            { 

                new Customer { Id = 1, FirstName = "Alfred" } ,

                new Customer { Id = 2, FirstName = "Max" } 

            } 

        };

​

        var someTypeDto = mapper.Map<SomeType, SomeTypeDto>(someType);

        Console.WriteLine(JsonConvert.SerializeObject(someTypeDto));

    }

}

​

public class SomeType {

    public int Id {get; set;}

    public List<Customer> Customers {get; set;}

}

​

public class Customer {

     public int Id {get; set;}

     public string FirstName {get; set;}

}

​

public class CustomerDto {

    public int Id {get; set;}

    public string FirstName {get; set;}

}

​

public class SomeTypeDto {

    public int Id {get; set;}

    public List<object> SomeValues {get; set;}

}