how to get equipments based on distance from firestore and use it in streambuilder?

Question

I am using streambuilder to fetch documents from firestore and pass individual data to listTile . I want to put a condition to fetch only equipments within 10 km range. In my database , the location is in the format of geopoint [latitute,longitude]. I used geoquery to restrict the equipments within particular range. But I got to know that it only fetches based on latitude and not longitude. How to run a geo "nearby" query with firestore? - from this answer it is clear that we have to use geohashes for this query. But I am not sure exactly where to use it in my code. Below is my code

 Expanded(
            child: TabBarView(
            children: _site == BestTutorSite.sell
                ? [
                    equipmentListStreamBuilder(
                        'SellEquipments', 'equipmentType.Tractor'),
                    equipmentListStreamBuilder(
                        'SellEquipments', 'equipmentType.Implement'),
                    equipmentListStreamBuilder(
                        'SellEquipments', 'equipmentType.Harvester'),
                  ]
                : [
                    equipmentListStreamBuilder(
                        'RentEquipments', 'equipmentType.Tractor'),
                    equipmentListStreamBuilder(
                        'RentEquipments', 'equipmentType.Implement'),
                    equipmentListStreamBuilder(
                        'RentEquipments', 'equipmentType.Harvester'),
                  ]),)

 StreamBuilder<QuerySnapshot<Object?>> equipmentListStreamBuilder(
  collectionName, eType) {
return StreamBuilder<QuerySnapshot>(
  stream: FirebaseFirestore.instance
      .collection(collectionName)
      .where("equipmentType", isEqualTo: eType)
      .where("geopoint", isLessThan: greaterGeopoint)
      .where("geopoint", isGreaterThan: lesserGeopoint)          
      .snapshots(),
  builder: (context, snapshot) {
    return !snapshot.hasData
        ? Center(child: CircularProgressIndicator())
        : ListView.builder(
            itemCount: snapshot.data!.docs.length,
            itemBuilder: (context, index) {
              DocumentSnapshot data = snapshot.data!.docs[index];
             return ListTile(
                leading: Icon(Icons.car_rental),
                title: Text(data['brand'].toString()),
                subtitle: Text("prem"),
                trailing: Icon(Icons.more_vert),
              );
            },
          );
  },
);

getNearByEquipments(double latitude, double longitude, double distance) {
print("---------inside getequipments");
// ~1 mile of lat and lon in degrees
double lat = 0.0144927536231884;
double lon = 0.0181818181818182;

double lowerLat = latitude - (lat * distance);

double lowerLon = longitude - (lon * distance);

double greaterLat = latitude + (lat * distance);
double greaterLon = longitude + (lon * distance);
setState(() {
  lesserGeopoint = GeoPoint(lowerLat, lowerLon);
  greaterGeopoint = GeoPoint(greaterLat, greaterLon);
});

}