Data::Dumper is a good example how to print a data structure. It is also not difficult to write a recursive sub that does a similar thing. See below. You could also add a callback function that searches for whatever. I made some assumptions about the data structure you are looking at but I think my example is relatively general.

use strict;
use Data::Dumper;

my %hash;
$hash{Company_A}{ Identifier_1 } = ["a", "b"]; 
$hash{Company_A}{ Identifier_2 } = ["b", "g"];                        
+      
$hash{Company_A}{ Identifier_3 } = "c"; 

$hash{Company_B}{ Identifier_1 } = "a"; 
$hash{Company_B}{ Identifier_2 } = "g"; 
$hash{Company_B}{ Identifier_3 } = "x"; 

print Dumper(%hash);

traverse( 0, \%hash );

sub traverse {
  my $level = shift;
  my $ref = shift;
  if( ref($ref) =~ /HASH/ ) {
    print "\n";
    for my $key (keys %$ref) {
      print "\t" x $level, $key;
      traverse( $level+1, $$ref{$key} );
    }
  } elsif( ref($ref) =~ /ARRAY/ ) {
    print "\n";
    for (@$ref) {
      print "\t" x $level;
      traverse( $level+1, $_ );
    }
  } else {
    print "\t" x $level, $ref, "\n";
  }
}
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