python - Flask-admin + flask_mongoengine loading one select box value depends on the value of other select box -

i using flask-admin + flask-mongoengine create admin panel website. have similar below models

class carmake(db.document):     name = stringfield()  class carmodel(db.document):     name = stringfield()     car_make = referencefield(carmake)  class car(db.document):     car_make = referencefield(carmake)     car_model = referencefield(carmodel) 

i admin page (create page car) user selects car make (select box) , depends on car make, car model select box should loaded models. googling problem. if me relevant documentation or sample programs advanced thanks.

also know embedding carmodels document inside carmake efficient or above design good?