Hi and welcome to the forums!!! It is considered best practice around here to post ddl and sample data in a consumable format. You can read about how to post that by following the link in my signature for best practices.

The biggest challenge I see here is that there does not appear to any way to sort your tax table accurately. The only value you have listed are strings (Tax1, Tax2 etc). This is fine to have a name for the taxes but you need to have someway to sort them (and sorting by strings is not the best choice). What happens if you have a third nested tax calculation? You have to know which order to process these calculations to get it correct.