Users Name shows both first and last name

Hi lisa@EW,

I'm sorry, but I don't follow you. Please explain using some screenshots. 

HI Astghik thans for responding!

I've attached a screen shot. 

Hi lisa@EW,

I'm sorry, but wpDiscuz doesn't have such an option. You need to use the following code. Put it in your current active theme function.php file:

add_filter('wpdiscuz_comment_author', 'custom_comment_author_name', 10,2);

if (!function_exists('custom_comment_author_name')) {
function custom_comment_author_name($authorName, $comment){
  if (strpos($authorName, ' ') !== false) {
     $authorNameData = explode(' ', $authorName); 
     $authorName = $authorNameData[0];
  }
    return $authorName;
  } 
}