Creating a Cascading Link Menu

Define “cascading link menu”.

You have the Main link and when you mouse over or click on the main link, more links will show. So basically you have an upper link, then sub-links that would not show until you mouse over or click on it. Hope that makes sense.
They have one that is a Java Script, here is the link https://javascript.internet.com/navigation/category-menus.html This is what I would like to do, but for the WP. Can this be done?

Found another one that might work. https://javascript.internet.com/navigation/click-to-expand-menu.html

Depending on which section of the menu/sidebar do you want to use this.
You should search for “fold”
e.g.
fold menu
fold category
and similar keywords

Well I think I may have found my answer. Thank you for your help. The fold is what sent me in the right direction.
Have a great day. Thanks again.
Cathie