Matching one of two fields with $in and $elemMatch - node.js

Question

Combining $in and $elemMatch
I'm trying to find a partial match for an employee's first or last name. I tried using the $or operator, but Mongo doesn't seem to recognize it.
Where am I going wrong?
router.get('/employees', async (req, res, next) => {
if(req.query.name) {
const response = await Companies.find({ employees:
{
$elemMatch: {
$in: [
{ first_name:new RegExp(req.query.name, 'i') },
{ last_name:new RegExp(req.query.name, 'i') }
]
}
}
})
res.json({ response })
}
else { next() }
})
My schema looks like this:
const companies = new mongoose.Schema({
company: [{
name: { type:String, required:true },
contact_email: { type:String, required:true },
employees: [{
first_name:String,
last_name:String,
preferred_name:String,
position: { type:String },
birthday: { type:Date },
email: { type:String },
}],
}]
}, {
timestamps: { createdAt: 'created_at', updatedAt: 'updated_at' }
})
I have some names in there that should match (including just "nna"), but sending a get request to /employees?name=nna just returns an empty response array.

Answer 1

the most convenient way to get employees back would be to unwind and then match like so:
db.Companies.aggregate({
"$unwind": "$employees"
}, {
"$project": {
"employees": "$employees",
"_id": 0
}
}, {
"$match": {
"$or": [
{
"employees.first_name": /anna/i
},
{
"employees.last_name": /anna/i
}
]
}
})
on the other hand, if the goal is to get the companies back, then this would work:
db.Companies.find({
"employees": {
"$elemMatch": {
"$or": [
{
"first_name": /anna/i
},
{
"last_name": /anna/i
}
]
}
}
})