I’ve found it.
/*** Adding extra field to get the the user who creates the another user during ADD NEW USER ***/
function custom_user_profile_fields($user){
if(is_object($user))
$created_by = esc_attr( get_the_author_meta( 'created_by', $user->ID ) );
else
$created_by = null;
?>
<h3>Extra profile information</h3>
<table class="form-table">
<tr>
<th><label for="created_by">Created By</label></th>
<td>
<input type="text" class="regular-text" name="created_by" value="<?php echo $created_by; ?>" id="created_by" /><br />
<span class="description">The person who creates this user</span>
</td>
</tr>
</table>
<?php
}
add_action( 'show_user_profile', 'custom_user_profile_fields' );
add_action( 'edit_user_profile', 'custom_user_profile_fields' );
add_action( "user_new_form", "custom_user_profile_fields" );
function save_custom_user_profile_fields($user_id){
# again do this only if you can
//if(!current_user_can('manage_options'))
// return false;
# save my custom field
update_user_meta($user_id, 'created_by', $_POST['created_by']);
}
add_action('user_register', 'save_custom_user_profile_fields');
add_action('profile_update', 'save_custom_user_profile_fields');
And then querying
the users by the custom field created_by
.. That’s it..