Hello, I saw this type of blog filter on a website and I really liked it. I was hoping I could add something similar on my site but I haven't found a way to do so without a plugin. If anyone has experience in this, please share, thanks! :^)
The filter that you see is not really a filter, it's just menu links. Each menu item such as the link that says "Support" will show posts that are in the "Support" category.
First go to WP > Posts > Categories and create a category called "Support". Then add posts to that category.
Go to WP > Appearance > Menus and add the category called "Support" into your menu. Users will now see all posts of "Support" when they click that menu link.