Update your second if
condition as shown below:
if (isset($this->request->get['information_id']) && $this->request->get['information_id'] == '{ID}') {
if (!$this->customer->isLogged() || $this->customer->getCustomerGroupId() != 1) { //where '1' is your customer groupid for which you want to give access..
$this->session->data['redirect'] = $this->url->link('information/information', 'information_id=' . $this->request->get['information_id']);
$this->redirect($this->url->link('account/login', '', 'SSL'));
}
}
$this->customer->getCustomerGroupId()
- returns your customer group id.
Have a nice day :) !!