Hi @kweng,
It's a neat display of data, isn't it? These kernel density histograms were added to Graph Builder in JMP 15. Once you are showing the Histogram element, toggle "Kernel Density" as the Histogram Style in the control panel on the left.
julian_0-1613492669807.png
Here's a short video showing all the steps to make that graph using the Big Class sample data table.
I hope this helps!
@jules