just want to ask if there is a better way of doing this

That depends on what makes one solution "better" than another and also how representative your sample set is.

use strict;
use warnings;

use Test::More;

my @set = (
    {
        file => '-/yf/-/22211_01_09_2000_XYz.pdf',
        zip  => '22211'
    },
    {
        file => '_/gt/-/02239_04_04_1989_PkW.pdf',
        zip  => '02239'
    },
    {
        file => '-/xy/-/02239_04_04_1989_PkW.pdf',
        zip  => '02239'
    },
);

plan tests => 2 * @set;

for my $datum (@set) {
    is zip_substr ($datum->{file}), $datum->{zip}, "Substr for $datum-
+>{file}";
    is zip_regex  ($datum->{file}), $datum->{zip}, "Regex  for $datum-
+>{file}";
}

sub zip_substr {
    return substr (shift, 7, 5);
}

sub zip_regex {
    my ($zip) = shift =~ m#/(\d{5})_#a;
    return $zip;
}
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