using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

    public static void Test()

    {

        var models = new List<TestModel>();

        models.Add(new TestModel(){Id= 0, Value = new string []{"a","b","c"}});

        models.Add(new TestModel(){Id= 1, Value = new string []{"d","e","f"}});

        models.Add(new TestModel(){Id= 2, Value = new string []{"g","h","i"}});

        models.Add(new TestModel(){Id= 3, Value = new string []{"j","k","l"}});

​

        var groups = models.GroupBy(model => new {model.Id,model.Value});

        foreach(var group in groups)

        {

            var test = group.SelectMany(p => p.Value);

        }

    }

}

​

public class TestModel

{

    public int Id {get;set;}

    public string[] Value {get;set;}

}