Filter and sort by custom field in Flask-admin ModelView

I want to add filters for quantity (custom field) in Model View

class FarmerAdmin(ModelView):

    column_descriptions = dict(amount = "All Transactions Total (Rs.)")

    column_searchable_list = ('name','village','phone')

    column_editable_list = ('phone',)

    column_filters = ('village','area',\
                  filters.FloatGreaterFilter('amount','Amount'))

    inline_models = (Transaction,)

    def get_query(self):
        return self.session.query(
            Farmer.id.label("id"),
            Farmer.name.label("name"),
            Farmer.village.label("village"),
            Farmer.phone.label("phone"),
            Farmer.area.label("area"),
            func.sum(Transaction.total).label("amount")
            ).join(Transaction).group_by(Farmer.id)

    def scaffold_sortable_columns(self):
        return {'id':'id','name':'name','village':'village',\
            'area':'area','amount':'amount'}

    def scaffold_list_columns(self):
        return ['id','name','village','phone','area','amount']


    def __init__(self, session):
        super(FarmerAdmin, self).__init__(Farmer, session)

      

        
        
        
      

    

Sorting works great by overriding the scaffold_sortable_columns method. Is there a way to add standard filters (more than less) for the quantity column.