using System;

using System.Linq;

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

public class Program

{

    public static void Main()

    {

        string json = @"

        [

            {

                        ""json_geometry"" : {

            ""type"" : ""MultiLineString"",

            ""coordinates"" : [

                [

                    [ 5.3164836419, 51.5857529419, 8.489 ],

                    [ 5.316526283, 51.5857224333, 8.489 ]

                ],

                [

                    [ 5.316526283, 51.5857224333, 8.489 ],

                    [ 5.3168490217, 51.5854915038, 8.489 ]

                ],

                [

                    [ 5.3168198838, 51.5854768709, 8.489 ],

                    [ 5.316772723, 51.5855193137, 8.489 ],

                    [ 5.316724102, 51.5855635173, 8.489 ],

                    [ 5.3166681579, 51.5856126962, 8.489 ],

                    [ 5.3166051849, 51.5856630663, 8.489 ],

                    [ 5.3165611838, 51.5856960728, 8.489 ],

                    [ 5.316526283, 51.5857224333, 8.489 ]

                ]

                ]

                }

            }

        ]";

        JArray array = JArray.Parse(json);

        var sorted = array[0]["json_geometry"]["coordinates"].SelectMany(p=>p).ToList();

        //Console.WriteLine(sorted.ToString(Formatting.Indented));

        foreach (var item in sorted) {

            Console.WriteLine(item.ToString());

            //break;

        }

    }

}