Reincorparate objects that have been dragged out of a scroll box back into it

Hello everyone, I tried searching on this issue, but I don't think I am using the correct keywords.
I had a large list of radio buttons that were put into a scroll box by a previous developer. I has to update the list. In order to alphabetize the list memebers, I dragged those that were not in order to the side of the slide, out of the scroll box. When the moved item came up in the alphbetization, I dragged it back in, but it remained listed as a separate object in the timeline and did not reincorporate back into the scroll. 

How do I fix this?