Update contents of one field based off contents of another

Update contents of one field based off contents of another

Hi community!

I'm looking for a way to automatically updated one field (a picklist) based off the text content of another field.

E.g.
IF "Country" is one of 'China, Japan, Singapore, South Korea' THEN "Region" is 'APAC'
IF "Country" is one of 'United States, Canada, Mexico' THEN "Region" is 'NAMER'

Relatively new to Zoho CRM, so any pointers on where to get started hugely appreciated!