node.js - Populate nested array in mongoose -

how can populate "components" in example document:

  {     "__v": 1,     "_id": "5252875356f64d6d28000001",     "pages": [       {         "__v": 1,         "_id": "5252875a56f64d6d28000002",         "page": {           "components": [             "525287a01877a68528000001"           ]         }       }     ],     "author": "book author",     "title": "book title"   } 

this js document mongoose:

  project.findbyid(id).populate('pages').exec(function(err, project) {     res.json(project);   }); 

mongoose 4.5 support this

project.find(query)   .populate({       path: 'pages',      populate: {        path: 'components',        model: 'component'      }    })   .exec(function(err, docs) {});