Animate RectTransform anchoredPosition relatively to other RectTransform

Hello there,

I'm trying to set up a cool animation of the UI: I wanted to ease in a container while easing in with a small delay a button inside the container.

The problem is that in the Animation View the only animable property available for the RectTransform is anchoredPosition, which is fine in most cases but a pain if the parent's anchoredPosition is being animated as well.

What I want is to be able to animate the button relatively to the container's parent, so that the animation curve is a simple ease curve with a small delay.

A "global position" would be nice but I understand there's no such concept when dealing with the UI system (or is there?).

The curves of a working animation using the anchoredPosition are the following:

The container

The button

Note: if the button curve is changed even a little bit, the results would be horrible. The timings must match precisely. That is why I'm trying to look for a different approach.