Can't find WordPress.org Page plugin!

Hi,

I have been searching for hours for a plugin i want to install on my page but i can’t find it anywhere.

I need something like what WordPress.org uses on their pages where they have WITHIN the page a ‘mini’ menu bar where you can choose different information and the pages change for that ‘topic’. If you have a look at this page: https://wordpress.org/plugins/responsive-google-effect-portfolio-grid/ they have description, installation, FAQ etc etc across the menu within the page and as you go along and choose different topics the information changes along with in.

Please help!!