This is the same feature I need. I have four properties that are wrapped under two loans. One loan is a commercial bank loan. The other is technically an unsecured personal loan that I used as a down payment but I track it as being against these properties.
I just found out about this site a couple of days ago and finished uploading all of our properties a few minutes ago. This feature would really help me decide to get rid of the excel sheet that I am currently tracking everything on.