my @data = (
[ { FIRSTNAME => 'Someother',
LASTNAME => 'Name',
ADDRESS => '123 4nd St.'}
],
[ { FIRSTNAME => 'Charlie',
LASTNAME => 'Piper',
ADDRESS => '123 2nd St.'}
],
[ { FIRSTNAME => 'First',
LASTNAME => 'Name',
ADDRESS => '123 3nd St.'}
],
);

sub complex_arrays {
$a->[0]->{FIRSTNAME} cmp $b->[0]->{FIRSTNAME} ||
$a->[0]->{LASTNAME} cmp $b->[0]->{LASTNAME} ||
$a->[0]->{ADDRESS} cmp $b->[0]->{ADDRESS};
}

my @sorted = sort complex_arrays @data;

print 'Sorted:' . $/ . '-' x 20 . $/;
foreach (@sorted) {
print "$_->[0]->{FIRSTNAME} $_->[0]->{LASTNAME} lives at $_->[0]->{ADDRESS}$/";
}