If you know exactly which paper you want, but aren't sure which list it sits in, you can locate it using the Global Search at the top of the Paper Selection screen.
Expand the Global Search, type your paper code into the field, and select 'Search'. Then next to your paper, select 'Locate'.
MyWaikato will tell you how many lists your paper is located in. Scroll down to see them. Then select 'Add' next to your paper, from the list you prefer.
If the paper you want is not in your lists, it may not meet the requirements of your qualification. To take it, you may need to apply for special permission.