I think you're making this too complicated. Check the docs for Getopt::Long. The last part of the section Options with multiple values shows how to do what you want. 
use feature qw(say);
use strict;
use warnings;

use Getopt::Long;

my( @opt_a, @opt_b );

GetOptions(
           'a=s{2}' => \@opt_a,
           'b=s{2}' => \@opt_b,
          );

say "@opt_a";
say "@opt_b";

[download]
On the command line: 
./pm-886569 -a a1 a2 -b b1 b2
a1 a2
b1 b2

[download]
This example specifies exactly two arguments/parameters for each option, but note that you can specify a range for the number of options, if needed.

In reply to Re: GetOpts::long Multiple Parameters per option by broomduster
in thread GetOpts::long Multiple Parameters per option by PyrexKidd

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