#!/usr/bin/perl
use warnings;
use strict;
use Data::Dumper;

my %info = (
     level_a => {
                1 => {
                  name  => "a",
                  loc   => "b",
                  },
               },

     level_b => {
                2 => {
                  name  => "c",
                  loc   => "d",

                  },
                },

     level_c => {
                3 => {
                  name  => "e",
                  loc   => "f",
                  }
               }
);


delete $info{'level_b'} or warn $!;

#the following delete creates $info{'level_b'}{2} ??
delete $info{'level_b'}{2}{'name'} or warn $!;

#delete $info{'level_b'} or warn $!; #works fine 

print Dumper(%info);