In mongoose can I create a virtual which populates and then filters the populated documents?

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MongoDB

mongoose

I have a model ItemModel and another model, ItemInstances. Hopefully those names are self-explanatory. I want to create a virtual in my Mongoose ItemSchema that will return the number of ItemInstances that are associated with that Item and that have a status of "In Stock". So far, I've been able to populate the ItemInstances via a virtual property in the ItemSchema, as so:

ItemSchema.virtual('numberInStock', {
    ref: 'ItemInstance',
    localField: '_id',
    foreignField: 'item',
});

This successfully populates the associated ItemInstances (gives me an array). This is the array that is returned:

[
  {
    _id: new ObjectId("619be4da2f47a46f785a473a"),
    item: new ObjectId("619be4d92f47a46f785a472c"),
    status: 'Damaged',
    __v: 0
  },
  {
    _id: new ObjectId("619be4da2f47a46f785a473c"),
    item: new ObjectId("619be4d92f47a46f785a472c"),
    status: 'In Stock',
    __v: 0
  },
  {
    _id: new ObjectId("619be4da2f47a46f785a473b"),
    item: new ObjectId("619be4d92f47a46f785a472c"),
    status: 'In Stock',
    __v: 0
  }
]

I want the virtual itself to filter the ItemInstances that have a status of "In Stock", and then return the number of those.

I know that I could filter the results in a query, but that's not my intention.

What I have tried:

The above. I also tried creating a getter, but I discovered that getter's cannot be async.