@Szymon thanks! This is so much better and can work if necessary, but it’s not exactly what I’m looking for.

What you described shows the items listed as follows:

  1. 2.     3.    4.   5. 
    
  2. 7.     8.    9.  10.  
    
        1. 15

I’d like the order be as follows:
1 4 7 10. 13
2. 5. 8 11. 14
3. 6. 9. 12. 15

Does that make sense?