$ cat pm_1190415/external/external_hash
%hash = (
    scopeX => {
        modelA => [qw{XA XA XA}],
        modelB => [qw{XB XB XB}],
    },
    scopeY => {
        modelA => [qw{YA YA YA}],
        modelB => [qw{YB YB YB}],
    },
    scopeZ => {
        modelA => [qw{ZA ZA ZA}],
        modelB => [qw{ZB ZB ZB}],
    },
);

1;

##</code><code>##

#!/usr/bin/env perl -l

use strict;
use warnings;

use File::Spec;

my ($dir, $file) = qw{pm_1190415/external external_hash};

my $extern_hash = get_extern_hash($dir, $file);

print "@{$extern_hash->{scopeX}{modelB}}";
print "@{$extern_hash->{scopeZ}{modelA}}";

sub get_extern_hash {
    my $path = File::Spec::->catfile(@_);
    our %hash;
    require $path;
    return \%hash;
}

##</code><code>##

XB XB XB
ZA ZA ZA