Layer animation - Adding new animation step
You can add new animations steps from the Animation manager which you can reach by clicking on the More button at the In, Loop or Out animation.
When you click on the More button a new window will pop up, which looks like this:
You can add a new animation step at the Animation settings section
It will create a new step where the same Animation settings are available.
Changing the order of the animation steps
You can change the order of the animation steps by dragging them.