How to reference nested object into other collection Mongodb
If each User has one Venue, you can reference User instead of Venue in Event. If a User may have more than one Venue, you better make Venues a seperate collection and reference both in User and Event.
Try this.
class Venue{ //Getter and Setter }class User{ private String name; @DBRef private Venue venue; //Getter and Setter }class Event { @DBRef private Venue venue; //Getter and Setter }