Swift Firestore query with filter for documents near me

Question

I have an iOS app that has employees that need to be notified of pickups nearby. I want to perform a Firestore query and filter the radius of documents returned. I came up with this solution

but @Frank van Puffelen pointed out my question may be an x y problem and he was right!

I want is to listen to firebase Firestore for documents added then return results near my location. My documents have geopoint and geohash data. Is there a way to write a query in swift that has a listener attached and filters for documents within 100 miles? This is my current query in swift:

extension Firestore {
    var pickups: Query {
        return collection("pickups").whereField("employeeUID", isEqualTo: "none").order(by: 
"date")
    }
}
func getPickups() {
    listener = db.pickups.addSnapshotListener({ (snap, error) in
        guard let documents = snap?.documents else { return }
        for document in documents {
            let data = document.data()
            let newPickup = PickUps(data: data) 
            self.pickups.append(newPickup)
        }
    })
}

Any ideas about a query would be greatly appreciated - Thank you!