Hello @Marc_Justin_Rait ,
To group the cities by region automatically, you may create a new view Groups by region, then use the Group by field function and select the field Region. Every time you will input the city and the region, it will automatically group the cities by their respective region.
Initial view :
In the view Groups by Region, you will see this :
To learn more about the function, feel free to check this illustrated article :
https://support.airtable.com/docs/guide-to-grouped-records
I hope that helps :slightly_smiling_face: