Like this: 

my %form;

my %field = (
    'key 1' => 'value 1',
    'key 2' => 'value 2',
);

$form{another_hash} = \%field;

for my $first_key ( keys %form ) {
    for my $hoh_keys ( keys %{ $form{$first_key} } ) {
        print $hoh_keys, $/;    ## get the keys
    }
}

[download]
You can also check perldsc. or **Specifically: Access and Printing of a HASH OF HASHES
You really can use Data::Dumper to see how the data structure looks like, then you can get at what you want. 
use Data::Dumper;
...
print Dumper \%form;

[download]
produces.. 
$VAR1 = {
          'another_hash' => {
                              'key 2' => 'value 2',
                              'key 1' => 'value 1'
                            }
        };

[download]
** Updates.

If you tell me, I'll forget.
If you show me, I'll remember.
if you involve me, I'll understand.
--- Author unknown to me

In reply to Re: Getting Keys From Hash In a Hash by 2teez
in thread Getting Keys From Hash In a Hash by HalNineThousand

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