#!/usr/bin/perl

use strict;
use warnings;

use Data::Dumper;

my %hash;

$hash{'1.dim'}{'2.dim1'}="wert1";
$hash{'1.dim'}{'2.dim2'}="wert2";
$hash{'1.dim'}{'2.dim3'}="wert3";
$hash{'1.dim'}{'2.dim4'}="wert4";

print Dumper \%hash;

$hash{'1.dim'}="wert";

print Dumper \%hash;