In a hash, can we have three keys combined together that point to one value?

I have a doubt in the below hash declaration:

%metadataHash is a hash

line 1: $metadataHash->{"name"} = $name;
line 2: $metadataHash->{"type"} = $Type;
line 3: $metadataHash->{"student"}{$file}{"math"} = "/$file";
line 4: $metadataHash->{"student"}{$file}{"phy"} = $phy;
line 5: $metadataHash->{"student"}{$file}{"chem"} = $chem;

In line 1 and line 2, it is clear that keys ("name", "type") and values ($name, $Type).

But in line 3,

• can we have three keys {"student"}{$file}{"math"} combined together that point to one value?
• In line 3, are they combined together in such a way considered as one key or three different keys?

$metadataHash->{"fastq"}{$file1}{"read1"} is shorthand syntax for $metadataHash->{"fastq"}->{$file1}->{"read1"}.

It deals with hashes where a value is a reference to another hash.

To explain with a demonstration:

#!/usr/bin/perl

use strict;
use warnings;

my $foo = {};

$foo->{a}{b}{c} = 1;

use Data::Dumper;

print Dumper($foo);

Gives:

$VAR1 = {
          'a' => {
                   'b' => {
                            'c' => 1
                          }
                 }
        };