How to get x, y from an element of ColumnLayout?

[michal.19937]

Hello,
Consider the code:

import QtQuick
import QtQuick.Layouts

Window {
    width: 640
    height: 480
    visible: true
    title: qsTr("Hello World")
    ColumnLayout {
        anchors.fill: parent
        Rectangle {
            id: re
            width: 200
            height: 100
            color: "red"
        }
    }
    Rectangle {
        x: mapFromItem(re, 0, 0).x
        y: mapFromItem(re, 0, 0).y
        z: 1
        width: 100
        height: 50
        color: "green"
    }
}

I'm trying to position the green rectangle on top of the red one, however it always lands in the top left corner of the window. If I replace ColumnLayout with Rectangle, the code works as intended, so ColumnLayout must be the problem.
How do I get correct x and y of the red rectangle?

[jsulm]

@michal.19937 Put an item in the layout. In that item you put the red rectangle and then the green one at the same coordinates (whatever the reason you want to do this).