How to keep ghosts visible

I would like to keep an animated object's path with ghosts visible while I animate another object. I require this for coordinating 2 objects' paths and destination.

I used to be able to option-click on the red diamond below an object that I had animated so that I could keep its path visible while it was deselected and I was working on animating the path of another object. This no longer functions - the path disappears when I click away.

Is there another way to keep the ghosts visible now with a different shortcut?

Thank you.