using System;
using System.Text.RegularExpressions;
using System.IO;
using System.Linq;
public class Test
{
	public static void Main()
	{
		var input = "abc(test)def(rst(another test)uv)xy";
		var regex = new Regex(@"(?=(\(([^()]+| (?<Level>\()| (?<-Level>\)))+(?(Level)(?!))\)))", RegexOptions.IgnorePatternWhitespace);
		var results = regex.Matches(input).Cast<Match>()
		               .Select(p => p.Groups[1].Value)
		               .ToList();
		Console.WriteLine(String.Join(", ", results));
	}
}

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