Here is some basic rolling backup for Foggy Mountain Breakdown. Being able to do a simple rolling backup and vamping rhythm for each song you play is an essential skill if you plan on jamming with others. Get the basics down, then try some licks. Remember, backup means we also back off our volume. Practice controlling dynamics on your own so you'll be able to play at an appropriate volume when backing up a soloist at a jam.
In this arrangement we have a simple pattern that works great for rolling backup. Note, pinch, note, pinch, and a forward backward roll. The notes and pinches are half as fast as the roll. Having these at the start of each measure really helps to establish solid and steady rhythm by playing something simple and strong. You may want to use the focus feature to really work on nailing precise timing. If you get really comfortable with measures 1, 3 and 7 the main arrangement shouldn't be much of a problem. Always listen to and read the banjo tab before playing. Think of ways to practice efficiently, and effectively for whatever you need to work on.