What buttons are you talking about? I don't see any of these anywhere. I've tried clicking on all elements that might be buttons in the top right area of the screen, and nothing there does anything. I don't see anything that looks like a slider.
I don't see anyway to rearrange the position of my hand cards - that would be really handy if I could do it, but I just can't find any of the UI elements you're talking about. I do see a pin to let the hand float at the bottom, or have a fixed position above my forest - it's a toggle. It doesn't let me arrange the cards.
Using Google Chrome on mac if that matters, but I also just tried looking on Safari on an iPad and I don't see any of these there either.
Not being able to resize the cards in my forest has been one of my main frustrations about the UI, so it's weird to hear that I'm actually supposed to be able to do it, but it's just not there at all. Very mystified.