Linking to a specific tab in a Tab Section with a custom button, not header

Hi, I’m trying to figure out the proper way to link to another tab from within tab content, and not from the tab header… just using the #id label of the tab I’d like to jump to doesn’t seem to work, I’ve tried hacking out the right sections from the tab navigation itself but haven’t had any success. You can see the page I’m working on here: http://vividbridgestudio.com/approach-2/ – my goal is to have the triangle images at the bottom of the tab sections function as next/previous buttons, primarily for mobile, but no luck so far. Any help appreciated, thanks!