This code should enable different user levels to add/ edit custom fields in the Wordpress. Solution to http://wpquestions.com/question/showChronoLoggedIn/id/9118

code.php

<?php
add_action( 'user_profile_update_errors', 'validate_field' );

function validate_field(&$errors, $update = null, &$user  = null)

{

if($user->has_cap('s2member_level2')) { // Custom fields only display to business accounts
// Nested if to check for field(s)
    if ($_POST['exp_years']=='' or $_POST['exp_years']==NULL) // Change to check for empty or any regular expression. 

    {

        $errors->add('empty_exp_years', "ERROR: Please select a valid value for exp years!");

    }
}else if($user->has_cap('s2member_level3')) {
  // Do this
}else {
  // Do that!
  
}
}

?>

Solution for http://wpquestions.com/question/showLoggedIn/id/9118