I need to apply mortgage interest to the home office. I used it for 8 months only. I added 2 mortgage records and split interest. What about other fields from 1098?

Help recommends to create separate mortgage records one for 8 months and another one for rest 4 months, split interest correspondingly and then check one for 8 months for the home office. The problem is that when I create 2 mortgages it asks about other fields from 1098 form and I have only one that form. How to input all of that boxes? Should I put the same values to both mortgages or split it somehow?