Insert ancestors of a category and id of that category to a new sub category

Here is my mongo collection

{
       "_id" : ObjectId("56dd4694227412331af170da"),
       "ancestors" : [
           {
               "_id" : ObjectId("56dd26ed227412331af170d9")
           }
       ],   
       "cat_title" : "craft beer",  
   }

Now i want to create a new sub category under "craft beer" which contain list of ancestors using laravel molequents.

via Chebli Mohamed