To be more specific, I have one slide with several transitions. Let's say I have three stand-alone objects, all of which all move from left to right, and each ends up with a different opacity at the end.
I'd like the next slide to simply reverse those transitions. The three objects would move from right to left, and each returns to its original opacity.
To be clear, I don't want to backup in the presentation -- I want this to happen on the next slide. But I don't want to re-create all those transitions in reverse.
You would do this all on a single slide, since the objects are the same.
You need to use Builds not transitions. If the objects are to move onto and then off the slide you use Builds, if the objects stay on the slide you would use Action builds or Smart Builds. See page 116 of the User Manual.