Jquery dropdown menu

Hello everyone, I've started leaing about web-design few months ago and i came to jquery, I was wondering if someone can show me how to make a dropdown menu but like horizontal style, https://www.bearbiology.com/ like this one when you hover over the "Bears of the world", it shows up the li tags of the list,
I guess it is a hidden div that appears on hover, there are a lot of tutorials for all sorts of dropdown menus but i couldn't find anything for this style.
If someone can show me how to make it would be of great help. :)