Example of deep populate for mongo with mongoose

mongo-populate.js

var q = keystone.list('IconographyPage')
                .model
                .find()
                .lean()
                .populate({
                  path: 'iconSections',
                  populate: { path: 'icons' }
                });

q.exec(function (err, results) {
  locals.data = results[0];
  next();
});