I have to say, I really don’t understand this stuff at all but I’m going to keep on trying…!
I have a panel docked to the bottom of the screen. When it’s clicked I want it to slide down off the screen. Therefore I want it to slide down the screen an amount that is the height of the panel, eg:
There’s several things you could use to achieve the desired effect. Keywords for further exploring: RelativeTo, RelativeNode, Translation, and UX Expressions.
Here’s a little something I threw together as a proof of concept to show off a couple of approaches you could take: