You can use the source model <source_model>Magento\Customer\Model\Config\Source\Group\Multiselect</source_model> to get the customer groups.

But its does not return the group ‘NOT LOGGED IN’ .so I have created new model to have ‘NOT LOGGED IN’ in the list.

<source_model>PHPCodez\Hideprice\Model\Config\Source\Group\Multiselect</source_model>

<?php
namespace PHPCodez\Hideprice\Model\Config\Source\Group;
use \Magento\Customer\Model\ResourceModel\Group\Collection;

class Multiselect implements \Magento\Framework\Option\ArrayInterface {

protected $_customerGroup;

protected $_options;

public function __construct( Collection $customerGroup ) {
$this->_customerGroup = $customerGroup;
}

public function toOptionArray() {
if (!$this->_options) {
$this->_options = $this->_customerGroup->toOptionArray();
}
return $this->_options;
}
}