I have the following code, (note I am talking about c#/.net here since some of this is subtly different in other variants of regex):

var str = @"abc(?<cg1>.*)def(?<cg2>((?<cg3>[0-9])-)+)";
var regex = new Regex(str);
var test = "abcxyzdef1-2-3-";
var match = regex.Match(test);

This matches strings like this:

abc  xyz  def  1-2-3-
abc
     .*                    This is called cg1
          def         
               ([0-9]-)+   This is called cg2

However, I also have an embedded group in cg2 where each digit is its own group – cg3.
So test running this the groups I got are:

match[0]:       abcxyzdef1-2-3-
match[1].       3-
match[2].  cg1  xyz
match[3].  cg2  1-2-3-
match[4].  cg3  3

It seems that cg3 only captures the last instance of that group, namely the last 3.
Is there a way using groups to get all instances where cg3 matched, or would I have to get cg2 and rerun the match just on that? Viz:

var cg2 = match.Groups["cg2"];
var innerRegex = new Regex("(?<digit>[0-9])-");
var innerMatches = innerRegex.Matches(cg2.Value);
foreach (Match m in innerMatches)
{
    Debug.WriteLine(m.Groups["digit"].Value);
}