//DevicesListPopup.qml

PopupWindow {
    id: root

    property var deviceModel

    Item {
        id: popupContent
        anchors.fill: parent

        Label {
            id: headerText
            text: "Please choose device"
        }

        ListView {
            id: deviceList
            model: root.deviceModel
            delegate: RadioButton {
                .....
            }
            .....
        }
    }
}


//DevicesMenu.qml

Item {
    id: root

    Button {
        id: button
        text: "Choose Device"
        onClicked: {
            var pos = button.mapToItem(root, button.width/2, button.height/2);
            devicesListPopup.originItemX = pos.x;
            devicesListPopup.originItemY = pos.y;
            deviceListPopup.visible = true;
        }
    }
    ......
    DevicesListPopup {
        width: 910
        height: 500
        id: devicesListPopup
    }
}