Algorithm::Loops's NestedLoops would handle this nicely. 

use Algorithm::Loops qw( NestedLoops );

my @AoA1 = (
   [ 'a', 'b', 'c' ],
   [ 'd', 'e', ''  ],
   [ 'f', 'g', ''  ],
   [ 'h', '',  ''  ],
);

my @AoA2 = NestedLoops(\@AoA1, sub { [ @_ ] } );

[download]

To use less memory: 

use Algorithm::Loops qw( NestedLoops );

my @AoA1 = (
   [ 'a', 'b', 'c' ],
   [ 'd', 'e', ''  ],
   [ 'f', 'g', ''  ],
   [ 'h', '',  ''  ],
);

my @AoA2;
my $iter = NestedLoops(\@AoA1);
my @list;
while (@list = $iter->()) {
   push @AoA2, [ @list ];
}

[download]

By the way, since you have two identical values in @{$AoA1[3]}, @AoA2 will contain many duplicates.

Untested.

Update: The above don't produce the results in the order you described. If the order matters, change

In reply to Re: 2D array ALL combinations by ikegami
in thread 2D array ALL combinations by FFRANK

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