...
our @memoList;
our $rxNest;
$rxNest = qr
   {(?x)
       (
       \(
       (?:
           (?>[^()]+)
       |
           (??{$rxNest})
       )*
       \)
       )
       (?{push @memoList, $+})
...
    if($string =~ /$rxNest/)
    {
        print "     Match succeeded\n";
        print "     $_\n" for @memoList;
    }
    else
    {
        print "     Match failed\n";
    }
...