[{"exist":66658,"warehouse":[{"stock_I":"available","prod_st":"active","last_sale":"2022-11-23","factura_uv":154368244,"price":8},{"stock_II":"available","prod_st":"active","last_sale":"2022-04-18","factura_uv":879624124,"price":8},{"stock_III":"available","prod_st":"active","last_sale":"2021-07-05","factura_uv":357846988,"price":8}]}]

db.collection.aggregate([{$match:{"warehouse.stock_II":"available"}},{$set:{warehouse:{$filter:{input:"$warehouse",as:"w",cond:{$eq:["$$w.stock_II","available"]}}}}}])