$VAR1 = [
          undef,
          undef,
          'NETLIST'
        ];
$VAR1 = [
          undef,
          undef,
          undef,
          [
            undef,
            undef,
            'NETLIST'
          ]
        ];
$VAR1 = [
          undef,
          undef,
          undef,
          undef,
          [
            undef,
            undef,
            undef,
            [
              undef,
              undef,
              'NETLIST'
            ]
          ]
        ];

##</code><code>##

my $ranges = [
               { I => 2 },
               { I => 3, J => 2 },
               { I => 4, J => 3, K => 2 },
               { I => 5, J => 4, K => 3, L => 2 }
             ];

for my $h ( @$ranges ) {
    my $array = 'NETLIST';
    for my $k (reverse sort keys %$h ) {
        my $a;
        $a->[$h->{$k}] = $array;
        $array = $a;
    }
    # ...
    print Dumper $array;
}

##</code><code>##

$VAR1 = [
          undef,
          undef,
          'NETLIST'
        ];
$VAR1 = [
          undef,
          undef,
          undef,
          [
            undef,
            undef,
            'NETLIST'
          ]
        ];
$VAR1 = [
          undef,
          undef,
          undef,
          undef,
          [
            undef,
            undef,
            undef,
            [
              undef,
              undef,
              'NETLIST'
            ]
          ]
        ];
$VAR1 = [
          undef,
          undef,
          undef,
          undef,
          undef,
          [
            undef,
            undef,
            undef,
            undef,
            [
              undef,
              undef,
              undef,
              [
                undef,
                undef,
                'NETLIST'
              ]
            ]
          ]
        ];

##</code><code>##

$array->[4]->[3]->[2] = $netlist;