There is a straight forward iterative solution:

my @list1 = qw/item1 item2 item3/;
my @list2 = qw/item1 item2 item4 item5/;
my %hash;
my $hr = \%hash;

$hash{item1}{item2}{item3} = 3;
$hash{item1}{item2}{item4}{item5} = 4;

$hr = $hr->{$_} for (@list1);
print $hr;

$hr = \%hash;
$hr = $hr->{$_} for (@list2);
print $hr;
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-- Hofmator