Mongoose: Populating with projection using attribute of scheme

I triying the following **population/projection** and work fine

modelBaby.findOne({'userId': req.user.data._id, '_id': req.params.id})
.populate('categories._categoryId', {
levels:{
$elemMatch:{
name: 'PURPLE'
}
}
})

But i need name as a variable something like:

modelBaby.findOne({'userId': req.user.data._id, '_id': req.params.id})
.populate('categories._categoryId', {
levels:{
$elemMatch:{
// over heree !!
name: 'categories._levelName' or this._levelName
}
}
})

the scheme ref is

const babyCategory = new mongoose.Schema(
{
answer: {type: String},
_categoryId: {type: Schema.Types.ObjectId, required: true, ref: 'category'},
_categoryName: {type: String, required: true},
_levelName: {type: String, required: true}
},
{versionKey: false, _id : false}
);

**This is possible ?** or how is the best way to approach this

Thanks btw =D

Start with the modelBaby.findOne().populate() query and the babyCategory schema shown in the issue, then read Mongoose population and projection documentation. Reproduce the fixed-name query and the variable-name case to establish the supported behavior; done means the issue has a confirmed capability answer or a documented recommended approach.

Written by the indexing model from the issue text.