不太清楚你是怎么做的，但你可能会这样做：

$query = .... /*your query code here*/
  ->orderBy('created_at', 'DESC')
  ->join('hr_applicants', 'hr_applications.hr_applicant_id', '=', 'hr_applicants.id')
  ->orderBy('hr_applicants.name', 'ASC');

if ($condition1) {
  $query = $query->orderBy('table.column', 'ASC');
} else {
  $query = $query->orderBy('table.column2', 'DESC');
}

$result = $query->get();