Two CMS lists in-line with horizontal scroll

I used some horizontal scroll tutorial to display my collection list in a horizontal scroll. Now I would like to show two lists in one horizontal scroll. I dont think i necessarily need to use some coding to combine them. I would like to force them to be next to each other in the horizontal scroll.
In the link you can see first the horizontal scroll how it workes and below the two lists that currently show below of each other.
Thanks for your help, much appreciated