How to configure "SUBSET FILTER FORMULA" properly in Imply data cube

With Imply UI's latest "SUBSET FILTER FORMULA" feature, users can filter out the unrelated data by default right at start of opening a data cube. 

However, sometimes when a filter is added for a column, the output shows 0 result. For example, user wants to filter only rows with only `Country Iso Code` = `US` in the Wikipedia data source:

But the result shows 0 results 

ROOT CAUSE: The problem is admin configured SUBSET FILTER FORMULA using the NAME in the configuration, instead of the actual COLUMN:

After the configuration change, the output shows up correctly.