Warning! Timeline view for Free and Pro plans are limited to 3. keep this is mind if you’re planning to duplicate this example. I recommend taking some inspiration and copying the formula into your own timeline database if this limitation occurs.
Timeline Progress
Formula
if(format(round(100 * prop("Child Progress") * 100) / 100) + "%" == "100%", "⭐️⭐️⭐️⭐️⭐️", if(empty(prop("Children Tasks")), "", slice("⏣⏣⏣⏣⏣⏣⏣⏣⏣⏣✓", 0, prop("Child Progress") * 10) + " | " + format(round(100 * prop("Child Progress") * 100) / 100) + "%"))