using System;
using System.Text.RegularExpressions;
using System.Linq;
using System.Collections.Generic;
public class Test
{
	public static void Main()
	{
		var txt = "[he[[llo][qw[[qwe:]sdsdfsdf [note2]";
		var res = Regex.Match(txt, @"^(\[[^]]*])+");
		Console.WriteLine(res.Value);
		var captures = res.Groups[1].Captures.Cast<Capture>().Select(p => p.Value).ToList();
		Console.WriteLine(string.Join(", ", captures));
	}
}