Returning the column name for only the filled cells

[fahmidik]

Hi everyone, 

I have the following example data set. The complete data set is rather large and picking out manually would be time consuming and inefficient. I would like to know which numbers (Part Description) are going to which lines (Line #). Only the filled cells for the corresponding part description indicate that the number goes to that line. For example in this table, Part Description 90033689 goes to Line 4 and 6. 

Could someone please guide me on which commands can be used here? Do I need VBA? 

Thank you for reading!

[#2]

@fahmidik 

When you say to be dealing with a "rather large" data set, consider using Power Query. Then you can fairly easily flatten the data (i.e. unpivot) and than group by Part Description. It's flexible, easy to maintain, though it requires a Refresh when the underlying data changes.

An example is attached.