Angularjs 如何仅显示基于其他源选择的ng选项中的值？

我有一个ng选项代码，当选择了客户时，它会显示职务。我的问题是这样的：

客户A-2职务

客户B-10个职位

问题： 当我点击客户端A时，它显示客户端A的2个职位，这是正确的，但当我点击客户端A之后的客户端B时，它显示10个职位，但前2个职位来自客户端A

请参阅下面的代码：

JS:

$scope.getClientJobTitles = function() {
        $scope.job_titles = [];
        $.each($scope.job_title_list, function (key, value) {
            if ($scope.client_id == value.client_id) {
                $scope.job_titles.push(value);
            }
        });
        $scope.vacancy_id = $scope.job_titles.length ? $scope.job_titles[0].vacancy_id : null;
    }

 private function generateCloneVacancyForm()
    {
        $form = new CForm('clone-vacancy-form');
        $form->addSelect('clone_client_id', $this->getClients(), NULL, FALSE, array_merge(CForm::$input_box_attrib, [
            'ng-model' => 'client_id',
            'ng-change' => 'getClientJobTitles()'
        ]));
        $form->addSelect('clone_vacancy_id', [], NULL, FALSE, array_merge(CForm::$input_box_attrib, [
            'ng-model' => 'vacancy_id',
            'ng-options' => 'item.vacancy_id as item.job_title for item in job_titles track by $index',
        ]));
        $form->addSubmit('clone-vacancy-btn', 'Submit', ['class' => 'btn btn-primary']);
        $form->setLabel('clone_client_id', 'Client Name');
        $form->setLabel('clone_vacancy_id', 'Job Title');
        $form->massSetRequired(['clone_client_id', 'clone_vacancy_id']);

        return $form;
    }

Laravel:

$scope.getClientJobTitles = function() {
        $scope.job_titles = [];
        $.each($scope.job_title_list, function (key, value) {
            if ($scope.client_id == value.client_id) {
                $scope.job_titles.push(value);
            }
        });
        $scope.vacancy_id = $scope.job_titles.length ? $scope.job_titles[0].vacancy_id : null;
    }

 private function generateCloneVacancyForm()
    {
        $form = new CForm('clone-vacancy-form');
        $form->addSelect('clone_client_id', $this->getClients(), NULL, FALSE, array_merge(CForm::$input_box_attrib, [
            'ng-model' => 'client_id',
            'ng-change' => 'getClientJobTitles()'
        ]));
        $form->addSelect('clone_vacancy_id', [], NULL, FALSE, array_merge(CForm::$input_box_attrib, [
            'ng-model' => 'vacancy_id',
            'ng-options' => 'item.vacancy_id as item.job_title for item in job_titles track by $index',
        ]));
        $form->addSubmit('clone-vacancy-btn', 'Submit', ['class' => 'btn btn-primary']);
        $form->setLabel('clone_client_id', 'Client Name');
        $form->setLabel('clone_vacancy_id', 'Job Title');
        $form->massSetRequired(['clone_client_id', 'clone_vacancy_id']);

        return $form;
    }

有什么想法吗