const foo = x => {
var y = x * 2

return function bar(z) {
  if (z.length > 3) {
    return z.map(
      (baz = v => {
        if (v > 3) return v + y
        else return baz(v * 4)
      })
    )
  } else {
    var obj = []
    const bam = () => {
      obj.length = 1
      obj[0] = this.w
    }
    setTimeout(bam.bind(this), 100)

    return obj
  }
}

I wanna convert "bar" function to arrow function, so what should i do with the 2 "this" inside?