Why reopen the directory again to look for files matching $1-$2-$3? You are going to see those filenames eventually. Just populate the hash as you go, and let things fall into place. Use a 2nd layer of hashing with the date as the key, then you can sort on the date later as you need. You may want to consider doing a deep hash, with each part of the filename acting as a key at some level. You can still get sorted retrievals given the first 3 components as a key.

my %files;

foreach (readdir(MYDIR)) {
    if (/([^-]+)-([^-]+)-([^-]+)-([^-]+)\.(pdf|html)/) {

        # using temp variables for illustrative purposes

        my ($name, $country, $language, $date) = ($1, $2, $3, $4);
        $files{$name}{$country}{$langauge}{$date} = $_;

        # alternatively for a less nested hash, you could do
        # $files{ join '-', $name, $country, $language }{$date} = $_;
    }

}

#### later

sub get_files_by_key {
    my ($name, $country, $language) = @_;

    my $hash_ref = $files{$name}{$country}{$language};

    # alternatively
    # my $hash_ref = $files{ join '-', $name, $country, $language };

    # in any case, sorting them here is easy
    return map { $hash_ref->{$_} } sort keys %$hash_ref;
}

my @relevant_files = get_files_by_key('foo', 'us', 'en');
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Obviously after reading this tale, you'll know that I'm unworthy to receive your assistance, but I beg to receive it.

Hey, this isn't the Internet Oracle. No need to supplicate!

ZOT,

blokhead