db={"users":[{"_id":1,"isActive":true},{"_id":2,"isActive":false}],"products":[{"_id":1,"ownerId":1,"description":"Product 1"},{"_id":2,"ownerId":2,"description":"Product 2"},{"_id":3,"ownerId":1,"description":"Product 3"}]}

db.products.aggregate([{"$lookup":{"from":"users","localField":"ownerId","foreignField":"_id","as":"owner"}},{"$match":{"owner.isActive":true}}])