$ perl -Mstrict -Mwarnings -E '
    use constant { FIRST => 0, SECOND => 1, THIRD => 2 };
    my @data = qw{ A:C:1 A:C:2 A:D:1 A:D:2 B:C:1 B:C:2 B:D:1 B:D:2 };
    say "Raw data:";
    say for @data;
    say "Sorted data:";
    say join ":" => @$_ for sort {
        $b->[FIRST] cmp $a->[FIRST]
        ||
        $a->[SECOND] cmp $b->[SECOND]
        ||
        $b->[THIRD] <=> $a->[THIRD]
    } map { [ split /:/ ] } @data;
'
Raw data:
A:C:1
A:C:2
A:D:1
A:D:2
B:C:1
B:C:2
B:D:1
B:D:2
Sorted data:
B:C:2
B:C:1
B:D:2
B:D:1
A:C:2
A:C:1
A:D:2
A:D:1

##</code><code>##

$a->[LAST_NAME] cmp $b->[LAST_NAME] || $a->[FIRST_NAME] cmp $b->[FIRST_NAME]