Accordion 3-tabs that allow you to create content that you can highlight based on selections.
This is an old thread. I'm not sure if this is what they meant, but I would also like to see an accordion menu feature added to Sway. This would make it easy for people to navigate through a long document and skip unnecessary information. For example, I am creating a manual and have different steps depending on a decision that is made. It would be nice to list out the decision and allow the reader to click it to see the necessary steps instead of having them scroll through all of the steps. An accordion menu feature would make this a lot easier and more visually appealing.
Darrell C Webster commented
To expand on your idea, you can currently group cards together. Add an option to make a group into a tabbed layout.
I gather that "the intent of group is to 'keep these items together' visually. How this is presented will vary based on your choice of mood." So far, I don't see the grouped layout affecting the presentation much. I just allows me to move a number of cards around at the same time.