Anna explained this in the post linked below, I believe that’s what you’re looking for.
Here is a cloneable version that you can copy:
Btw, I found that one using: https://showcasesearch.webflow.io which lets you search through all cloneable webflow projects that other people made, very handy.
I got all as I wanted but how to make the focused image bigger than the other ones like in the slider 12345 project, i can’t seem to get the hang of it