Mongoose: multiple query populate in a single call

In Mongoose, I can use a query populate to populate additional fields after a query. I can also populate multiple paths, such as ``` Person.find({}) .populate('books movie', 'title pages director') .exec() ``` However, this would generate a lookup on book gathering the fields for title, pages and director - and also a lookup on movie gathering the fields for title, pages and director as well. What I want is to get title and pages from books only, and director from movie. I could do something like this: ``` Person.find({}) .populate('books', 'title pages') .populate('movie', 'director') .exec() ``` which gives me the expected result and queries. But is there any way to have the behavior of the second snippet using a similar "single line" syntax like the first snippet? The reason for that, is that I want to programmatically determine the arguments for the populate function and feed it in. I cannot do that for multiple populate calls.