How to make a dimension be identified as a Geo dimension?

Hi all,

I'm using Lumira 1.18 and I met a problem. I want to use the Geo graphic but when I created the Geo hierarchy the lumira only identified the dimension called "country" and the dimension called "region" cannot be identified. The "region" contains the names of provinces of China. "province" can be regarded as the states in USA.

best regards,

Shuang