ONE way for many partnerships to accomplish this is a "drop down".

Look at the escrow statement of the sale.  Who were the seller(s)? 

How did the distribution of net proceeds done?   

IF a drop down was done with all T's crossed and I's dotted, the title would have been changed from the partnership to the partners at their %'s some time before the close of escrow - sometimes for a split nanosecond. 

In a "drop down", the partner who did an exchange had his/her net proceeds forwarded to the exchange facilitator.  The other partners got their shares.  If this was the scenario, the partnership had a distribution of asset (the real estate property).  Report the distribution (Basis and FMV info are required) and close the books for the partnership accordingly. 

Follow the economic substance.  Follow the money. 

If the seller was the partnership, work with the exchange company to see how the partner's  share could be exchanged.  Different localities may have different ways.   

Hope this helps.