Hi,

You can inherit res.partner and super this function and pass your new fields in res.partner

class ResPartner(models.Model):
    _inherit = "res.partner"

    @api.model
    def _formatting_address_fields(self):
        """Returns the list of address fields usable to format addresses."""
        return super(ResPartner, self)._formatting_address_fields() + ['new_field1']

Hope this will help you

Thanks