Custom Wordpress Pagination

Hello i need a custom pagination for 3 website. I need to divide the article in 3 or more part and to show in the point where i divide, 2 buttons, also responsive. You can see an exemple of what i want here: [login to view URL] I don't know if you need to use function or create a plugin. Before offering your work please think if you can do it so we don't lose any time.