EVOLUTION-NINJA

Edit File: edit_positions.php

<?php
/**
 * @package     Joomla.Administrator
 * @subpackage  com_modules
 *
 * @copyright   (C) 2012 Open Source Matters, Inc. <https://www.joomla.org>
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

defined('_JEXEC') or die;

JLoader::register('TemplatesHelper', JPATH_ADMINISTRATOR . '/components/com_templates/helpers/templates.php');

JHtml::addIncludePath(JPATH_COMPONENT . '/helpers/html');
$clientId       = $this->item->client_id;
$state          = 1;
$selectedPosition = $this->item->position;
$positions = JHtml::_('modules.positions', $clientId, $state, $selectedPosition);

// Add custom position to options
$customGroupText = JText::_('COM_MODULES_CUSTOM_POSITION');

// Build field
$attr = array(
	'id'          => 'jform_position',
	'list.select' => $this->item->position,
	'list.attr'   => 'class="chzn-custom-value" '
	. 'data-custom_group_text="' . $customGroupText . '" '
	. 'data-no_results_text="' . JText::_('COM_MODULES_ADD_CUSTOM_POSITION') . '" '
	. 'data-placeholder="' . JText::_('COM_MODULES_TYPE_OR_SELECT_POSITION') . '" '
);

echo JHtml::_('select.groupedlist', $positions, 'jform[position]', $attr);