Hi Michelle,
Thanks for the post. Currently, CODAP doesn’t support Connecting Lines for attributes on the right-hand side of the graph. I think the fall-back would be to create a second graph with the same x axis, but the right-hand y-axis attribute on the left. Not ideal, but at least you could compare the shapes of the two y-attributes.
Out of curiosity, would you say that the need for connecting lines for right-axis attributes was a common one? Should it be higher on our to-do list?
Jonathan