My join is not working

You haven't select your office.names, try this :

PHP Code:

$this->db->select('phones.users, phones.numbers');
           $this->db->select('offices.names');
           $this->db->from('phones');
           $this->db->join('offices', 'phones.offices = offices.id', 'left');
           $this->db->like('phones.users',$param);
           $this->db->or_like('phones.numbers', $param);
           $this->db->or_like('offices.names', $param);