use strict;
use warnings;

use Test::More;

my @tests = (
    {
        in => ' /x/y/z/a/b/c/d/e.f',
        want => '/c/d/e.f'
    }
);

plan tests => scalar @tests;

my $re = qr#((?:/[^/]*?){3})$#;

for my $t (@tests) {
    $t->{in} =~ $re;
    is $1, $t->{want}, "Extracted $t->{want}";
}