sub Foo::Bar::f {}

##</code><code>##

{
   package Foo::Bar;
   sub f {}
}

##</code><code>##

use strict;
use warnings;

sub Foo::f {
   our $var;
   print(__PACKAGE__, "\n");
   print("$var\n");
}

{
   package Bar;
   sub f {
      our $var;
      print(__PACKAGE__, "\n");
      print("$var\n");
   }
}

$main::var = 'main!';
$Foo::var = 'foo!';
$Bar::var = 'bar!';

Foo::f();
# main
# main!

Bar::f();
# Bar
# bar!