Mongoose referenced lookup collection field returned null in results

[OlammieAO]

I greet everyone Happy New Year in advance. Please I have this mongoose aggregate that returns the right records but do not include fields in the lookup collection i.e referenced collection.

******THIS IS MY SCHEMAS

===============USERS COLLECTION

const usersSchema = mongoose.Schema(
{
fullname: {
type: String,
required: [true, 'First Name cannot be empty'],
trim: true,
index: true,
},
email: {
type: String,
validate: [validator.isEmail, 'Provide a valid email'],
trim: true,
},
password: {
type: String,
required: [true, 'Password is required'],
},
}, {
timestamps: true,
},

);

const Users = mongoose.model('User', usersSchema);
module.exports = Users;

===============MOTORS COLLECTION

const sub_origin_info_schema = mongoose.Schema({

sub_garrage_user1: { //It is an object ID of users collection
type: String,
required: false,
},
garrage_name1: {
type: String,
required: false,
},
sub_garrage_user2: { //It is an object ID of users collection
type: String,
required: false,
},
garrage_name2: {
type: String,
required: false,
},

})

const motorSchema = new mongoose.Schema(
{
user_id:{
type: { type: Schema.Types.ObjectId, ref: 'User'},
},
garrage_of_origin_user:{ //It is an object ID of users collection
type: String,
required: true,
},

motor_code: {
    type: String,            
    required: true,
    unique: true,
},       
motor_name: {
    type: String,            
    required: true,
},
motor_number: {
    type: String,            
    required: true,
},
imo_number: {
    type: String,            
    required: true,
},
garrage_of_origin: {
    type: String,            
    required: true,
},

journey_date: {
type: String,
required: true,
},

sub_origin_garage: sub_origin_info_schema,

}, 

{
timestamps: true,
},
);

const Motors = mongoose.model('Motor', motorsSchema);
module.exports = Motors;

*******WHAT I WANT TO ACHIEVE

The query worked but does not work as perfectly. It doesn't include the fullname and email of the referenced Collection using the field mentioned.

I want to achieve two things,

1.) I want to pull the user details(fullname and email) from the Users collection using the garrage_of_origin_user field in the Motors schema collection. The query worked but the fullname and email are null i.e they were not pulled.

How do I pull details(fullname and email) of the users in the subdocument sub_origin_garrage array object which are "sub_garrage_user1" and "sub_garrage_user2" fields? Note that there are users in the subdocuments(sub_origin_garage) too. How do i use lookup to pull out the fields in the users collection for this 3 users i.e garrage_origin_user, sub_garrage_user1 and sub_garrage_user2 in one document?

*******THIS IS MY CODE

Motor.aggregate([
//{ $match : { '_id' : '674ed7fd61f952ddf3e4a661' } },
{ $unwind: "$sub_origin_garage" },
{ $unwind: "$sub_origin_garage.sub_garrage_user1" },
{ $match :
{ $or: [
{ 'sub_origin_garage.sub_garrage_user1' : '6750838a51d231d3178343c7' },
{ 'sub_origin_garage.sub_garrage_user2' : '6750838a51d231d319656209' },
]
}
},
{ $sort : {journey_date: -1} },
{
"$lookup": {
"from": "users",
"localField": "garrage_of_origin_user",
"foreignField": "_id",
"as": "motorDriver"
}
},
{ $project: {
motor_code: 1,
motor_name: 1,
motor_number: 1,
imo_number: 1,
garrage_of_origin: 1,
journey_date: 1,
'sub_origin_garage.garrage_name1': 1,
'sub_origin_garage.garrage_name2': 1,
motorDriver: { fullname: 1, email: 1 }
}
}

])
.then(response => {

  res.status(200).json({
    status: 'success', 
       response      
  });     
})
.catch(error => {
    res.json({
        message: `An error occured!: ${error}`
    })
})

I will appreciate your kind assistance.