How to add multiple circle on circular progress bar?

Question

I have implemented circular progress bar. but now i want to add multiple circles on progress bar. like below image

I have implemented below code

let rect = rectForShape()
let circlePath = UIBezierPath(arcCenter: CGPoint(x:rect.midX , y: rect.midY), radius: CGFloat(10), startAngle: CGFloat(50), endAngle: CGFloat(Double.pi * 2), clockwise: true)

let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.cgPath
// Change the fill color
shapeLayer.fillColor = UIColor.clear.cgColor
// You can change the stroke color
shapeLayer.strokeColor = UIColor.red.cgColor
// You can change the line width
shapeLayer.lineWidth = 3.0
view.layer.addSublayer(shapeLayer)