Cascading checkbox and stock the result as an object

I have a list of "dimensions" which contains a list of chapters which contains a list of items:

"dimension" : [{
                 "dimensionName" : String,
                 "chapters":[{
                             "chapterName" : String,
                             "items":{"itemName":String}
                            }]
              }]

what I want is to select the dimensions, chapter, and items in the same form of the original object("dimension" : [{"chapters":[{"items"}]}]).

this is my angular function to save the selected dimensions:

$scope.dimensionChanged = function(selected,dimension){
        if(!$cookies.newObject) $cookies.newObject=[];
        //the list to display chapters of selected dimension
        if(!$scope.chaptersList) $scope.chaptersList = [];
        for (var k in dimension.chapter) {
            if(selected === true){
                $cookies.newObject.push(dimension);
                    $scope.chaptersList.push(dimension.chapter[k]);
            }else{
                var index =              $scope.chaptersList.indexOf(dimension.chapter[k]);
                $scope.chaptersList.splice(index, 1);
            }
        }
    };

what I need to do now is choose chapters and stock them in the associated dimension, and the same thing for items.