Q: How to do nested queries in mongoose? This is answerModel in short. I am not getting expected results. I want some help knowing how to perform nested find queries using mongoose
"question_id": {
    "topics": [
        "curium"
    ],
    "_id": "5edb42f9a0b1c85754d6ca24",
    "questionText": "What actually is curium",
    "id": "5edb42f9a0b1c85754d6ca24"
}

and here's schema definition:
const answerSchema = new mongoose.Schema({
    question_id: {
        type: mongoose.Schema.ObjectId,
        ref: 'Questions',
        required: [true,'Answer must belongs to particular question']
    }
})

and I'm also using query middleware to populate before find query
answerSchema.pre(/^find/, function (next) {
    console.log('Populating answer schem')
    this.populate({
        path: 'question_id',
        select: 'questionText topics'
    });
    next();
})

console.log(req.params.topicaName);        // curium
const answers = await answerModel.find({'question_id.topics': req.params.topicaName });
console.log('answers are', answers)   // answers are [] 

and I am getting this output to console:
curium
Populating answer schem
answers are []

