How to override NULL values

Summary

How to override null value with values from another column in OBIEE Analysis

Content

When building an analysis in OBIEE, what would be the code to enter into the "Column Formula" box in "New Calculated Measure" if I want to create a new column where null values are override with existing values?

 

For example, in the enclosed screenshot I have the analysis shown on the left.  My goal is to fill the Null values with the first/only NOT NULL values in "Raw Materials" column per each product i.e A, B and C in Product column.  Result per dataset shown to the right.