Dual axis scrolling

Hi all, i found this website on the Webflow showcase - https://www.var-but.com/
And i really want to know to achieve the dual scrolling effect, having 2 columns, one scrolling up and down, and the second column scrolling left to right at the same time! I am actively currently trying to make it but i really have no idea, ive done basic horizontal scrolling, but nothing like this.

My read-only: Webflow - Will's Playground

Cheers,
Will