my $foo = [
                 { foo => { bar => 'baz' } },
         ];

         foreach my $foo_entry (@$foo)
         {
                 foreach (keys %$foo_entry)
                 {
                         if (defined($foo_entry->{$_}->{foo})
                          && defined($foo_entry->{$_}->{foo}->{bar}))
                         {
                                 return $foo_entry->{$_}->{foo}->{bar};
                         }
                 }

                 return;
         }