var shapeLayers: [String: CAShapeLayer] = [
    "rectangle": CAShapeLayer(),
    "ellipse1": CAShapeLayer(),
    "ellipse2": CAShapeLayer()...and so on
]

override func awakeFromNib() {
    wantsLayer = true

    for (_, shapeLayer) in shapeLayers {
        shapeLayer.lineWidth = borderWidth
        shapeLayer.strokeColor = ColorScheme.blue.cgColor
        shapeLayer.fillColor = ColorScheme.white.cgColor
        shapeLayer.path = nil
        shapeLayer.lineCap = kCALineCapSquare
        layer?.addSublayer(shapeLayer)
    }

    shapeLayers["rectangle"]?.fillColor = NSColor.clear.cgColor
}

override func draw(_ dirtyRect: NSRect) {
    let rectangle = CGMutablePath().addRect(selectionBounds)
    let ellipse1 = CGMutablePath().addEllipse(in: CGRect(origin: somePoint, size: someSize))
    let ellipse2 = CGMutablePath().addEllipse(in: CGRect(origin: somePoint, size: someSize))
    ...and so on

    shapeLayers["rectangle"]?.path = rectangle
    shapeLayers["ellipse1"]?.path = ellipse1
    shapeLayers["ellipse2"]?.path = ellipse2...and so on
}