using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Reflection;

using System.Text.Json;

​

public class Program

{

    public static void Main()

    {

        var values = new List<string>

        {

            "brachio_hl7_test1",

            "brachio_hl7_test2",

            "brachio_emeds_test1"

        };

        CreateTree(values);

    }

    private static void CreateTree(IEnumerable<string> values)

    {

        var tree = new List<(string, int, int?)>();

        var groups = values.Select(s => s.Split('_').Reverse().Skip(1).Reverse());

        int id = 0;

        foreach (var grp in groups)

        {

            foreach (string key in grp)

            {

                Console.WriteLine(key + " : " + id);

                id++;

            }

        }

    }

}