.where() by populated fields - mongodb

Question

I want to find the closest workers by his location which have a specific skill.
Location schema:
var schema = Schema({
name: String,
type: String, // home | latest
user: {type: Schema.Types.ObjectId, ref: 'User'},
address: String,
position: {
type: {type: String, default: 'Point'},
coordinates: [Number]
},
status: String // active | inactive
}, {collection: 'locations'});
Worker schema:
var schema = Schema({
username: String,
password: String,
firstName: {type: String, default: ''},
middleName: {type: String, default: ''},
lastName: {type: String, default: ''},
role: {type: String, default: 'user'}, // admin | user | worker
skills: [{
object: {type: Schema.Types.ObjectId, ref: 'Skill'},
slug: String, // Should remove in the future
ratePerHour: Number,
status: {type: String, default: 'active'} // active | inactive
}],
locations: [{type: Schema.Types.ObjectId, ref: 'Location'}]
}, {collection: 'users'});
Skill schema:
var schema = Schema({
name: String,
slug: String,
users: [{type: Schema.Types.ObjectId, ref: 'User'}],
isFeatured: Boolean,
minRatePerHour: Number,
maxRatePerHour: Number,
status: String // active | inactive | deleted
}, {collection: 'skills'});
Bellow is my query but .where() does not work with populated field.
Location
.find({
'position': {
$near: {
$geometry: {type: 'Point', coordinates: [lat, lng]},
$minDistance: 0,
$maxDistance: 20000
}
}
})
.populate('user')
.deepPopulate('user.skills.object')
.where({'user.skills': {$elemMatch: {'object.slug': 'cleaning'}}})
.limit(5)
.exec(callback);
Am I doing wrong with these schemas? Should I use embed document rather than ID reference?
Is there any way else to query?

Answer 1

You have to use special properties for populate as described here: Query conditions and other options
So I think you can get your results with something like this:
Location
.find({
'position': {
$near: {
$geometry: {
type: 'Point',
coordinates: [lat, lng]
},
$minDistance: 0,
$maxDistance: 20000
}
}
})
.populate({
path: 'user',
match: {
'skills': {
$elemMatch: {
'object.slug': 'cleaning'
}
}
},
options: {
limit: 5
}
})
.deepPopulate('user.skills.object')
.exec(callback);
Not tested, keep it only as example.