I'm not quite sure what you are trying to do but as far as my sleepy brain can understand you have lists nested to each JobStepList right? then are you trying to display the content of the nested collection in your row or something???. In the "Add To List" are you trying to add the selected item to the selected item nested collection? and what is the null exception you mentioned? i can't see anything on your picture. I just need more imput to completely understand what you are doing and provide you a solution. However if the scenario i described is what you are trying to do then i guess the selected item is your JobStepList class so you can use it to fill it with the selected item on your "Add To List" list. Btw i used to work on a Safety project as well many years ago. Your pictures and code reminds me a lot to what i had to deal with Samples on the net are usually messy and in my opinion nothing you should make a big use of. However they are quite useful sometimes as they can give you some ideas on how you can solve your problems.