I have a list where users can fill a column named "External effort (m/d)" (type of column is number). After that column, I have "External resource cost" column, which type is currency, and where users can write a cost of resource.
I would like to do a column validation, where if the column "External effort (m/d)" is filled, then it's required to fill "External resource cost" column. How would that function look for that column validation?