checkboxes dependentet from dropdownlist

As I mentioned in topic i try do depends checkboxes from dropdownlist. I fill data to my dropdownlist from controller:

 @RequestMapping(value = "/all", method = GET)
 public List<Warehouse> findAll(){
 return warehouseService.findAll();
 }

 $http
    .get('/api/warehouses/all')
    .then(function (response) {
        $scope.warehouses = response.data;
    });

Every Warehouse object have a List with package:

@OneToMany
private List<Package> packages = new ArrayList<>();

Now when i am creating Route and when i select one Warehouse from dropdownlist i wanna fill checkboxes from List from currently selected Warehouse.

Select Warehouse:

   <select ng-model="credentials.warehouseStart">
    <option ng-selected="credentials.warehouseStart == x" id="startId" ng-value="x" ng-repeat="x in warehouse" ></option>
</select>

And checkboxes:

   <div flex-xs flex="50">
    <md-checkbox aria-label="Select All"
                 ng-checked="isChecked()"
                 md-indeterminate="isIndeterminate()"
                 ng-click="toggleAll()">
        <span ng-if="isChecked()">Un-</span>Select All
    </md-checkbox>
</div>
<div class="demo-select-all-checkboxes" ng-model="credentials.packages" flex="100" ng-repeat="item in packages">
    <md-checkbox ng-checked="exists(item, selected)" ng-click="toggle(item, selected)">
            <p> </p>
            
    </md-checkbox>
</div>

Checkbox fill:

  $http
    .get('/api/package/all')
    .then(function (response) {
        $scope.packages = response.data;
    });

It is possible if i select one object in Dropdowlist(Warehouse) can i get a object id? Then i think i can get a correct chebkoxes by directive /package/all/{id} ?