TT has a note:
NOTE: If this is a full or partial disposition of a publicly traded partnership (PTP) or master limited partnership (MLP) that was reported to you on a Form 1099-B, enter a sales price of zero on line 5 and a basis of zero on line 7 below. Enter the 1099-B transaction on Schedule D, checking the appropriate "Reported on 1099-B" box A or B. See Help.
I do this when an MLP has both short term and long term gains.
I go to schedule D and click on the quick zoom box at top to open a 1099B worksheet to enter the sale data from the Sales Schedule.
I don't understand how TT realizes this sale is associated with the MLP but I always enter the MLP symbol on the worksheet and it seems to pick up carry-forwards from the K-1 and link the info properly.