Set select: false to subdocuments array at mongoose
Try creating a CommentSchema first,
var CommentSchema = new Schema({ user: ObjectId, content: String //whatever else});
and then in your PostSchema specify
comments: { type: [CommentSchema], select:false}
Well you could do this:
comments: { type: Array, default: [], select: false }
But you would be losing the declared structure underneath, otherwise what is really wrong with:
comments: [{ user: { type: ObjectId, select: false }, content: { type: String, select: false } createdAt: { type: Date, select: false }}]
Which may seem a bit terse, but likely someone thought it was sensible.