use Data::Dumper;
warn Dumper \%XYZ::Hash1;
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our (%Hash1, %Hash2, %Hash3);
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As zwon writes above, you can always access the hashes with their fully qualified notation %XYZ::Hash1, but you don't need Exporter for that in package XYZ.

However,if you make the hashes available to the caller via @EXPORT_OK, you can import them stating

use XYZ qw(%Hash1 %Hash2);
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which makes them accessible as %Hash1 and %Hash2 in the importing namespace.

print "$_ => $Hash1{$_}\n" for keys %Hash1;
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I tried both the methods, I am getting able to get only empty hash :(

Have you tried:

use strict;
use warnings;
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I see require Exporter; line is missed in your example.

Update: Here's the working code:

package XYZ;
use strict;
use warnings;
require Exporter;
our @ISA       = qw(Exporter);
our @EXPORT_OK = qw(%Hash1);
our ( %Hash1, %Hash2 );

sub populateHashRoutine {
    %Hash1 = ( a => 1, b => 2, );
    %Hash2 = ( c => 3, d => 4, );
}

1;
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use strict;
use warnings;
use Data::Dumper;
use XYZ qw(%Hash1);

XYZ::populateHashRoutine;
warn Dumper \%Hash1, \%XYZ::Hash2;
__END__
$VAR1 = {
          'a' => 1,
          'b' => 2
        };
$VAR2 = {
          'c' => 3,
          'd' => 4
        };
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Then it must be empty. Try outputting the hash inside the package.

package XYZ;
{
my %Hash1;
my %Hash2;
my %Hash3;

sub populateHashRoutine {

    # open the file "raw_file.txt"
    open (my $fh, '<', 'raw_file.txt') or die "raw_file: $!";
    
    # Populate %Hash1 %Hash2 %Hash3
    while (<$fh>) {
        # mumble, mumble, mumble 
    }

    close ($fh);
}

sub GetH1 {
    my $key = shift;
    return $Hash1{$key}
}

sub GetH2 {
    my $key = shift;
    return $Hash2{$key}
}

sub GetH3 {
    my $key = shift;
    return $Hash3{$key}
}

}
1;

#main.pl
#========
use XYZ;
XYZ::populateHashRoutine("raw_file.txt");

#How to print Hash1,Hash2,Hash3 values here ?

print XYZ::GetH1('key1'),"\n";
print XYZ::GetH2('key2'),"\n";
print XYZ::GetH3('key3'),"\n";
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package XYZ;

use strict;
use warnings;
use Data::Dumper;

require Exporter;
our @ISA         = qw(Exporter);
our %EXPORT_TAGS = (
    'all' => [
        qw(
          Hash1
          Hash2
          Hash3
          )
    ],
);
our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );
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Thanks for the tutorial. But it doesn't provide any explanation on using accessing multiple hashes