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

my $hash_ref;
my @array1 = qw( some_unique_key1 some_unique_key2 some_unique_key3 );
my @array2 = qw( meta_data_1 metadata_2 metadat_3 );
my @array3 = qw( submitted_date1 submitted_date2 submitted_date3 );

@{$hash_ref->{'Metadata'}}{ @array1 } = @array2;
@{$hash_ref->{'Submitted date'}}{ @array1 } = @array3;
print Dumper $hash_ref;