use Data::Dumper;

$VAR1 = {
  'misc' => {},
  'docs' => {
    'howtos' => {
      'email' => {
        'index.html' => {
          'date' => '21-1-2004',
          'size' => '691'
        }
      },
      'ftp' => {},
      'ssh' => {}
    }
  }
};

$fs = "/docs/howtos/email/";
$v = $VAR1;

# this is the actual processing
map { $v = $v->{$_} } grep { length > 0 } split m./., $fs ;

print Dumper $v;