mongoose find by nested object id conta code example
Example 1: mongoose nested object without id
var subSchema = mongoose.Schema({
//your subschema content
},{ _id : false });
Example 2: mongoose find by nested property
System.findOne({ 'nodes.main.Alpha': 23000}, function(err, system){
if(err){console.log(err);}
else{console.log(system);}
});