A brief look at the Step Editor
One of the most common complaints I hear from Logic users is that we cannot see multiple automation lanes in the Piano Roll editor. Logic Pro has another editor that does allow it, but for reasons I cannot understand, people have not taken to it.
In earlier versions, before 10.6., you would have seen it where you now see the Step Sequencer tab, but it has been devalued and now you must find it by going to the Window menu:
If it intrigues you, then it is well explained in the manual.