connected_field.html

<div class="input-group">
                        <select required tabindex="2" chosen class="chosen-select form-control {{aclass}}" style="{{astyle}}" tabindex="{{tabIndex}}" ng-model="ngModel" ng-options="value.name for value in {{ngModel}} track by value._id"> 
                        </select> 
                        <div class="input-group-btn">
                            <button id="quickaddd" data-toggle="tooltip" data-placement="top" title="{{atitle}}" data-original-title="Crear uno nuevo" class="btn btn-primary"><i class="fa fa-plus-square-o"></i> 
                            </button> 
                        </div>
                    </div>

ng-connected.js

function connectedField(){

 
 
  function Ctrl($scope, $rootScope, API){  //API viene de los servicios 
 
       // do the magic 
       
    
 
       API
       [$scope.ngEntity]()  //entity debe ser similar a su referencia en apiFactory, método que esta en el archivo controllers
       .get()
       .success(function(rs){      
          $scope[$scope.ngModel] = rs.data;   
          console.log($scope[$scope.ngModel])  
       });       
 

 
  }
 
 
  function Link(scope, element, attrs){
    //do something linking
  }
 
   return {
       restrict : 'AE',
       scope : 
       {
         ngModel : '@',
         ngEntity : '@',
         aclass : '@',
         astyle : '@',
         tabindex : '@'
       },
       templateUrl : 'views/connected_field.html',
       controller : Ctrl, 
       link : Link
   }
 


}

angular
    .module('inspinia')
    .directive('ngConnected', connectedField);

test.html

<ng-connected ng-model="miempresa" ng-entity="empresa"></ng-connected>