Join reference Table in mongoose/mongodb

I tried to pass the database from Mysql to Mongo and I have to do a join between all these models and get all the Users with their respective boxChica and that box with all its attachments and details, I know that in sql it is easier to do that Query, but I am missing that in mongoose/mongodb.

{usuario1: {...}, cajaChica: {detalleCajaChica {...}, anexos: {...}, usuario2: {...}, cajaChica: {detalleCajaChica {...}, anexos: {.. .}, ..., usuarioN: {...}, cajaChica: {detalleCajaChica {...}, anexos: {...}}

var usuarioSchema = new Schema({
  CORREO:{
    type: String,
    unique: true
  },
  TOKEN_PASS:   String,
  ROL:          String,
  AUTORIZACION: Number
});

var Usuario_CajaChicaSchema = new Schema({
  usuario: { type: Schema.ObjectId, ref: "Usuario"},
  cajaChica: { type: Schema.ObjectId, ref: "CajaChica"}
});

var cajaChicaSchema = new Schema({
  FECHA_ACTUAL:         Date,
  VALOR_TOTAL:          Number,
  VALOR_FONDO_FIJO:     Number,
  PORCENTAJE_CONSUMO:   Number,
  ESTADO_CAJA:          Number,
  APROBADO:             String 
});

var detalleCajaChicaSchema = new Schema({
  VALOR:            Number,
  NOMBRE_EMPRESA:   String,
  NOMBRE_CATEGORIA: String,
  NOMBRE_PROVEEDOR: String,
  RUC_CED:          String,
  NOMBRE_ENTREGADO: String,
  NOMBRE_CARGADO:   String,
  FECHA:            Date,
  DETALLE_CAJA:     String,
  cajaChica: { type: Schema.ObjectId, ref: "CajaChica"},
  anexo: { type: Schema.ObjectId, ref: "Anexos"}
});

var anexosSchema = new Schema({
  TIPO:         String,
  ESTAB_FAC:    String,
  PTO_FAC:      String,
  SEC_FAC:      String,
  AUTO_FAC:     String,
  PORC_FAC_IVA: String,
  BASE:         String,
  ESTAB_RET:    String,
  PTO_RET:      String,
  SEC_RET:      String,
  AUTO_RET:     String,
  cajaChica: { type: Schema.ObjectId, ref: "CajaChica"}
});

via Bakke Medina