Is this the only way to access the package contents? I do not permission to change the package namespaces (ie. package my_package; -> package dir_two::my_package; ). I want to leave these stuff untouched.

Ok, if you can't (or don't want to) change the .pm files you could try something like:

use Data::Dumper;
use vars qw(%my_package::my_hash);

sub my_special_require ($) {
    my $pkg = shift;
    require $pkg;
    # alias %my_package::my_hash to %main::my_hash (aka %my_hash)
    *my_hash = \%my_package::my_hash;
}

my_special_require "dir_one/my_package.pm";
print Dumper(\%my_hash);

my_special_require "dir_two/my_package.pm";
print Dumper(\%my_hash);
[download]

Or, simply access the hash from within your script fully qualified as %my_package::my_hash

Update: added use vars ... to make it run cleanly with -w