ios – SwiftUI Charts – show the purple tick on the backside outdoors the border

At the moment, right here is my supply code and screenshot of the pattern app I am doing. My solely concern is how can I present the purple tick outdoors the border on the backside half?

VStack(alignment: .main) {
            Chart {
                ForEach(chartData, id: .id) { merchandise in
                    LineMark(
                        x: .worth("Beat", merchandise.beat),
                        y: .worth("Worth", merchandise.worth)
                    )
                    .foregroundStyle(merchandise.sort.coloration.opacity(lineVisibility[item.type]!))
                    .foregroundStyle(by: .worth("Plot", merchandise.sort))
                    .lineStyle(.init(lineWidth: 2))
                }
            }
            .border(.black, width: 2)
            .chartLegend(.hidden)
            .chartYAxis(.hidden)
            .chartXAxis {
                AxisMarks(values: .automated(desiredCount: numberOfBeats, roundLowerBound: true, roundUpperBound: true)) { _ in
                    AxisGridLine(stroke: .init(lineWidth: 1)).foregroundStyle(Shade.grey)
                    AxisTick(centered: true, size: 20, stroke: .init(lineWidth: 1))
                        .foregroundStyle(Shade.purple)
                }
            }
            .padding(.trailing, 15)
            
            HStack {
                Textual content("0 beat")
                    .padding(.main, -15)
                Spacer()
                Textual content("(numberOfBeats) beat")
            }
        }
        .body(minWidth: GENERAL_WIDTH * 2)
        .padding(.trailing, 10)

Instance Chart