Вы можете использовать образец тестового примера, который я написал для вашей цели:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
namespace Rextester
{
public class Program
{
public static void Main(string[] args)
{
Dictionary<long, List<Tuple<object, Object>>> testDict = new Dictionary<long, List<Tuple<object, Object>>>();
testDict.Add(12345 , new List<Tuple<object, object>>(){
new Tuple<object, object>("developer1", "studio1"),
new Tuple<object, object>("developer1", "studio2"),
new Tuple<object, object>("developer1", "studio3")
});
foreach (KeyValuePair<long, List<Tuple<object, Object>>> kvp in testDict)
{
Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
foreach(Tuple<object, Object> tuple in kvp.Value)
{
Console.WriteLine("Item1 = {0}, Item2 = {1}", tuple.Item1, tuple.Item2);
}
}
}
}
}