You should use HoH (a Hash of Hashes)

my %HoH;
$a = "fruits";
$b = "birds";
$c = "p";
$d = "g";
$e = "c";
$HoH{$a}{$c}="peach";
$HoH{$a}{$d}="grapes";
$HoH{$b}{$c}="parrot";
$HoH{$b}{$e}="crow";

foreach my $k (keys %HoH) {
   foreach my $j (keys %{$HoH{$k}}) {
     print "\$HoH{$k}{$j} = $HoH{$k}{$j}\n";
   }
}
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see perlreftut