You can also try to create grouping column
Col Cumulative Sum(1, :Test ID, :Sample Type)
Use that with Split
And then select one row from control colum and fill with previous value
and cleanup (remove order column, re-order columns, rename if needed)
This works in this fairly simple case, but it is also fairly easy to loose data when using JMP's split platform so be careful with (order column tries to prevent this).
-Jarmo