Expand and collapse sub-sections

Hello,

perhaps a stupid idea, but I'll throw it in here anyhow:

Would an extra button that expands/collapses all sub-sections be helpful?
Sometimes I'm checking all countries and sub-sections in the country list and often I'm forced to open a serious amount of sub-sections before I find what I'm looking for.
But then ofcourse you have a very long list to scroll through, so clicking the button again would collapse all sub-sections in one click...

Just to be sure everybody knows what I'm talking about:

At the very bottom of the homepage you have a selection '>> View the country list with my collection quantities.'
That's the one I'm refering to... Instead of clicking through every sub-sections, you can open or close all of them with one click. Thereby removing the need to click, only scrolling 😄

Perhaps an even more advanced feature would be to have a button or drop-down menu that allows every user to open all sub-sections, or only the ones that contain a coin in his or hers collection?

I support this. Especially for sections with 4 levels of subsections, this would help a lot