Get all child and grand child task by Ref_row

[amufaamo]

Usually task and project has several hierarchy. Appsheet can take child task by Ref_row, but is it possible to take all child and grand child task?

For example, I have sheet like below

For example, United States includes California, and California includes Los Angeles. 

It means United States includes California and Los Angeles, so I want to take both California and Los Angeles by list.

Within is Enumlist, which can choose places

I made virtual column "include" like below. App formula is 

select(Sheet1[Place], in([_thisrow].[Place], [within]))

I could get "California" in "United States". But I also want to take grand child "Los Angeles". Is it possible ?