You'll actually create different K-1's for each sub-PTP.  Here's an answer to a similar question that explains why:  https://ttlc.intuit.com/questions/3892957?notification_token=ff3910567f6a79af2f27ca92310d395e

How does one calculate the basis in this instance? Since the basis information is given in Part II of the Supplemental K-1 how do you break down the basis for the different partnerships listed on the breakdown page?

It would get pretty complicated.  The "Current Year Increase (decrease)" line can be calculated, since it is equal to adding/subtracting the various numbers on the K-1 (adding lines 1-11 and then subtracting the deductions on subsequent lines).  But figuring out the other capital contributed and the withdrawals/distributions seems tricky.  Is there a reason you need to?  Its not required for filing.  You'd typically enter the info for the primary PTP, and leave it blank for the other flow-through entities.

On K-1 Supplemental Part III I may have more than one partner - how do I enter this information in the separate K-1's as part of my tax return?

I have the same issue with a K-1 from ET - there are 3 entities on the supplemental statement.   the problem i see is that the 3rd entity has a value in line 1 and line 2.   if the solution is to use the supplemental information then an entity in the supplemental statement should not have amounts in both columns.  that is the k1 issue to begin with that is forcing you to use the supplemental info to detail more than one k1 entry.  Advise?

@gradyquib Here's a much more recent question on ET that I just answered.  It should help you too:  https://ttlc.intuit.com/community/get-started-in-community/help/need-help-in-understanding-how-to-en...