use strict;
use warnings;

############################# OP data

# dummy items to play with
my @animals = (qw( cow camel dog cat  ));
my @foods   = (qw( fish pasture meat  ));
my @places  = (qw( wood sea    desert ));

# commands 
my $commands = {
    select => {
        completion_list => \@animals,
        commands => {
                        give => {
                                    completion_list => \@foods,
                        },
                        take_to => {
                                    completion_list => \@places,
                        },
        },
    },
    kill  => {
        completion_list => \@animals,
    }
};
#############################

my $branch = { commands => $commands };
my @path;

BRANCH: {
    if ( exists $branch-> { completion_list }) {
        my $choice = choose( @{ $branch-> { completion_list }}); 
        push @path, $choice
    }
    if ( exists $branch-> { commands }) {
        my $choice = choose( sort keys %{ $branch-> { commands }}); 
        push @path, $choice;
        $branch = $branch-> { commands }{ $choice };
        redo BRANCH
    }
}

sub choose { $_[ 0 ]}

print "Excellent choice! ===> [ @path ]\n";