การแบ่งหน้าด้วย pagination ติดตรงการเรียกผ่าน controllers ที่อยู่ใน Folder ครับ

$config['uri_segment'] = 5 ; // ลองเพิ่มตรงนี้เข้าไปดูครับ 
$config['base_url']	= base_url()."index.php/admin/menu/index";
$config['per_page']=1;
$config['total_rows']=$this->db->count_all('cmb_menu');
$this->pagination->initialize($config);

$this->db->select('mn_title,mn_path')->from('cmb_menu')->order_by('mn_order','DESC')
		->limit($config['per_page'],$this->uri->segment(3))->get()->result();

$config['uri_segment'] = 4 ; // ลองเพิ่มตรงนี้เข้าไปดูครับ 
$config['base_url']	= base_url('index.php/admin/menu/index');
$config['per_page']=1;
$config['total_rows']=$this->db->count_all('cmb_menu');
$this->pagination->initialize($config);

$this->db->select('mn_title,mn_path')->from('cmb_menu')->order_by('mn_order','DESC')
		->limit($config['per_page'],$this->uri->segment(4))->get()->result();

//+ Count total row for pagination
$num_row = $this->word_model->select_num_row(); 

//+ Config pagination
$config['uri_segment'] = 4 ;
$config['base_url'] = site_url('test/word/index/');
$config['total_rows'] = $num_row;
$config['per_page'] = '50'; 
$this->pagination->initialize( $pagination_config ); 
//- Config pagination

//+ Data
$Content['rs_word'] = $this->word_model->select_data( $config['per_page'] , $this->uri->segment(4) );