Any themes or features that give me drop downs like this website

go to https://concaveearth.site

Notice the theme? It’s X theme from Wordpress

I need something like this for discourse. The default theme just isn’t doing it , topics are hidden and hard to find unless you go digging

Notice the dropdown menus how it populates topics like that in those sections? Is this possible? I know there’s a plugin/extension for drop downs , is there any way to have it auto populate posts from Sections?

I want a drop down to mass view topics in sections like you can see on that website

I need a proper and decent menu , the general UI I don’t like for website engagement it just isn’t doing it