Here is one way to do what (I believe) You are requesting:
scrollingpage_JHSv1.hype.zip (15.8 KB)
There is some styling in the “Head HTML” section. The function “slideSelectIndicator” does all the work.
You can get fancier than this demo - such as automatically calculating the slide “break points” where the slide indicator moves from one to another. Currently these are manually set to change when the slide, either top or bottom, crosses the general “slide indicator” area.