Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I can’t find any active coupons for this product in Banggood.
Link: Banggood product page
Price: -3 USD
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGFLSZ, BGHOMEAPP, BGAFF7OFF, bGhOnEy10, BGSS10%SW, BGHome15%, BGHOMEAPP13, BGHOMEA13, BG10OFFAFF, BGwhielabel, 13f142, BG10OFFAFF1, 6GSGIT, 00c906, BG00c906, ADMITAD2212, 2022ACTIESNL, Terence, Tabby20, 2203ActiesNL, BG1efeb0, 8Couponsde, MVC8SPRING
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi Shunzao Z1/Z1 Pro Vacuum Cleaner Filter.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).