%inGroups = (
              'server02' => [
                              'serversC',
                              'serversD',
                              'serversB',
                              'serversA'
                            ],
              'server03' => [
                              'serversC'
                            ],
              'server04' => [
                              'serversB',
                              'serversA',
                              'serversC'
                            ]
            );

Server server02 is in groups serversA, serversB, serversC, serversD
Server server03 is in groups serversC
Server server04 is in groups serversA, serversB, serversC