When you work with Timelines, it’s easy to accidently interpolate twice. The TL is already sampling the necessary data; if you now plug in relative into A, you’ll get inconsistent results. Either prepare the data before the TL starts or use fixed values.
My drawer’s default X is 5 and it extends to 35, try it like so:
Note (upper left) how the Drawer is parented to the Shelf. With this setup, you can rotate the whole actor however you want and use relative X of the Drawer:
The timeline is a 0-1:
If your actor’s hierarchy is more complex, you may need to share how it’s set up. You can transform directions from local to world if necessary. Think of a robotic arm with 4 joints and a bunch of pistons - something is always relative to something else.