Error while pushing data into nested array of mongoose - node.js

Question

I am trying to push data in the treatment arrray which is nested in files array.
schema of patient:
var treatmentSchema = new Schema({
prescription:{
type : String,
},
record: {
data: Buffer,
contentType: String
}
});
var FileSchema = new Schema({
drName : {
type : String,
requried : true
},
desease :{
type:String,
requried:true
},
treatment : [treatmentSchema]
},{
timestamps : true
});
var patientSchema = new Schema({
pat_no:{
type:Number
},
username:{
type : String,
requried : true,
unique : true
},
DOB : {
type:Date
}
,
password:{
type : String,
requried : true,
unique : true
},
name : {
type : String,
requried : true
},
email:{
type : String,
requried : true
},
aadhar : {
type : String,
requried : true,
unique : true
},
image: {
data: Buffer,
contentType: String
},
nomeneeAadhar:{
type : String,
requried : true,
},
files : [FileSchema]
};
code:
Doctor.findById(req.cookies.user)
.then((doctor)=>{
var image={}
if(req.files)
{
image={
data: new Buffer(req.files.record.data,'base64'),
ctType: req.files.record.name.split('.').pop()
}
}
Patient.updateOne({"_id" :req.params.patID },
{
"$push": {
"files.$[t].treatment":{
"prescription":req.body.comment,
"record":image
}
}
},
{ arrayFilters: [ { "t.drname": doctor.name , "t.desease":req.body.dise } ]},
function(err, result){
if(err){
console.log(err)
}else if(!result){
//update not success
console.log("no success")
}else{
console.log(result)
console.log("success")
}
})
.then((doc)=>{
res.send(doc)
})
})
result:
{"n":1,"nModified":0,"ok":1}
I tried this method as well:
Doctor.findById(req.cookies.user)
.then((doctor)=>{
var image={}
if(req.files)
{
image={
data: new Buffer(req.files.record.data,'base64'),
ctType: req.files.record.name.split('.').pop()
}
}
Patient.updateOne(
{
_id:req.params.id,
"files.drName" :doctor.name,
"files.desease" :req.body.dise
},
{
$push :{
"files.$.treatment":{
"prescription":req.body.comment,
"record":image
}
}
}
)
.then((doc)=>{
res.send(doc)
})
})
DB connection:
var connect = mongoose.connect('mongodb://localhost:27017/doctor', {
useNewUrlParser: true,
useUnifiedTopology: true
})
.then((db) => {
console.log("Database Connected Successfully");
})
.catch((err) => {
var err = new Error("Error in Database connectivity");
return next(err);
})
Data not get updated in db.
please help!!
thank you!