Hi @Yun_Huang, thanks for the good question. If the cursor layer is set to the top layer, you are correct, you will not be able to select other elements natively underneath that layer, but you can also set the pointer events for the .cursor class in custom css to turn off the pointer events, to make the cursor layer behave with a “click-through” behavior.
I was trying to take a look at the site to test this, but it seems the read only link you shared is no longer valid.
From the screenshot it looks like the cursor layer has a class of “cursor”, so one possible solution (you will need to try it) is to add the following css to the head of the page in page settings, then publish the site.
The custom code may not render in the designer for this, but you can try that and see if putting the cursor layer to a higher z-index, then using the custom code if it works as expected on the published site.