Should the need arise to divide cremated remains again, go into one of the sub-portions and Divide again.
Note that you cannot divide again from the original set of cremated remains, as the Divide button no longer exists.
For a cemetery using byondpro's out-of-the-box numbering convention with a cremated remains record which has been divided and then a sub-portion has then been divided again, the records will be numbered as per below.