#!/usr/bin/perl

use warnings;
use strict;
use Data::Dumper;

my %groups = (
  group1 => { 'http://foo.com/' => {},
              'http://bar.com/' => {},
              'http://baz.com/' => {}, },
  group2 => { 'http://abc.com/' => {},
              'http://def.com/' => {},
              'http://ghi.com/' => {}, },
);

foreach my $group (sort keys %groups) {
  my $group_ref = $groups{$group};
  foreach my $url (sort keys %$group_ref) {
     my $url_ref = $group_ref->{$url};

# do stuff
     $url_ref->{result} = 200;
  }
}

print Dumper(\%groups);