Thanks to @don_crissti and @Archemar. I reckon my question is not a duplication of the above question.
So here is an example of input. Edit: All sections have values. I've added another complexity to the subheading (I should have done that).
DATA1 NAME: A (X) 12,1 13,2 14,4 NAME: B (X) 21,2 22,3 NAME: C (X) 24,4
The desired output should look like
DATA1 A 12,1 A 13,2 A 14,4 B 21,2 B 22,3 C 24,4