Layers

It looks like the sample you linked to in Review has each "tab" item on a separate slide.

• They forgot to hide the Prev and Next buttons on the "values" item. That's an accidental clue to how it was done.
• The tabs may have been on a Master layout. That's a good idea for setting up something like that, because it keeps the tabs in just one location, which makes it easier to update.

The same effect could be done with layers.

• To allow the user to easily move from one tab to another, have each layer show all the tabs on the base. (In your file, all the tabs except the selected one are hidden on the layers.) Then you don't need a "X" (close) button on the layers.
• Put the tabs into a button set. Then, when the user selects one tab, the others will automatically be deselected. Here's more info:  https://community.articulate.com/series/articulate-storyline-360/articles/articulate-storyline-360-user-guide-how-to-work-with-button-sets 
• Consider adding a short Fade Transition to the layers, so they blend when moving from one to another. Here's more info: https://community.articulate.com/series/articulate-storyline-360/articles/articulate-storyline-360-user-guide-how-to-add-transitions-to-slides-and-layers