How to do Domain Mapping/Masking

We have a wordpress mulsite site with multiple subsite. Below is the sample of a subsite url

Subsite 1: example.com/tw/en

We want to mask that domain and to show user example.com.tw/en or example.tw/en but at the same time then should still be able to access example.com/tw/en.

All these 3 domains: example.com/tw/en, example.com.tw/en, example.tw/en will show the same website.

How can we do it on nginx?