my %scored;

. . .

foreach my $a (@{ $array_ref }) {
    if (exists $scored{$a}) {
        # We've already scored this one
        push @{ $bar->{$scored{$a}}, $a;
        next;
    }

    my $i = 0;
    foreach my $b (split('-', $a)) {
        foreach my $c (keys %{ $hash_ref }) {
            $i += $foo->{$b}->{$c}->{'value'};
        }
    }
    $scored{$a} = $i;
    push @{ $bar->{$i} }, $a;
}