SliderWithButtons.swift

import SwiftUI

struct SliderWithButtons<LeftButton, RightButton>: View
where LeftButton: View, RightButton: View {
  @Binding var value: Double
  let range: ClosedRange<Double>
  let leftButton: () -> LeftButton
  let rightButton: () -> RightButton
  
  var body: some View {
    HStack  {
      Button { withAnimation { value = range.lowerBound } } label: { leftButton() }
      Slider(value: $value, in: range)
      Button { withAnimation { value = range.upperBound } } label: { rightButton() }
    }
  }
}

@available(iOS 16.0, *)
struct ContentView: View {
  @State var sliderValue = Double()
  
  var body: some View {
    SliderWithButtons(value: $sliderValue, range: 0...100) {
      Text("L")
    } rightButton: {
      Text("H")
    }
  }
}