To create a scrollable area you need to have a mask inside the layer group you want to make scrollable. Then select the layer group and click on the Scroll Area button in the Protowire panel. The layer group icon will then change to indicate it's a scrollable area. Whether a scrollable area scrolls vertically or horizontally or both depends on whether the content is longer and/or wider than the mask. It's a good idea to put your content in a symbol so you can see all of it without having to remove the mask. To remove the scrolling from a layer group, just select it and press the Remove Scroll button.