Combine two OR-queries with AND in Mongoose

I want to combine two OR-queries with AND in Monoose, like in this SQL statement:

SELECT * FROM ... WHERE (a = 1 OR b = 1) AND (c=1 OR d=1)

I tried this in a NodeJS module which only gets the model object from the main application:

/********** Main application ***********/var query = MyModel.find({});myModule1.addCondition(query);myModule2.addCondition(query);query.exec(...)/************ myModule1 ***************/exports.addCondition = function(query) {  query.or({a: 1}, {b: 1});}/************ myModule2 ***************/exports.addCondition = function(query) {  query.or({c: 1}, {d: 1});}

But this doesn't work, all OR-conditions will get joined together like in this SQL statement:

SELECT * FROM ... WHERE a = 1 OR b = 1 OR c=1 OR d=1

How can I combine the two conditions of myModule1 and myModule2 with AND in Mongoose?