use Data::Dumper;

my @arr1 = qw(2 4 5);
my @arr2 = ('1,nfs', '2,afp', '3,cifs', '4,dns', '5,backup');
my @arr3 = map { (split /,/)[-1] } grep { /^[@arr1],/x } @arr2;

print Dumper(\@arr3);

__output__

$VAR1 = [
          'afp',
          'dns',
          'backup'
        ];