merge widget PyQt5 like chrome window tab

how to combine 2 progressbar widgets into one widget when the user drags and drops to one of the widgets? MainWindowHide window must always be hidden and only used for progressbar initiation. I want widgets to be able to be dragged and dropped like chrome tabs and can be separated again. Thank you for your help.

this is my code:

import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QMainWindow

class Widget_Progressbar(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Widget_Progressbar, self).__init__(parent)
        self.setWindowTitle("Progress Bar")
        self.setWindowFlags(QtCore.Qt.WindowStaysOnTopHint)
        self.setGeometry(500, 500, 680, 80)
        self.progressBar = QtWidgets.QProgressBar(self)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.progressBar.sizePolicy().hasHeightForWidth())
        self.progressBar.setSizePolicy(sizePolicy)
        font = QtGui.QFont()
        font.setPointSize(8)
        self.progressBar.setFont(font)
        self.progressBar.setOrientation(QtCore.Qt.Horizontal)
        self.progressBar.setTextDirection(QtWidgets.QProgressBar.TopToBottom)
        self.progressBar.setAlignment(QtCore.Qt.AlignCenter)
        self.gridLayout = QtWidgets.QGridLayout(self)
        self.gridLayout.setObjectName("gridLayout")
        self.gridLayout.addWidget(self.progressBar, 0, 0, 1, 1)
        self.progressBar.setValue(50)

class MainWindowHide(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("Hide Main Window")
        self.setGeometry(100, 100, 800, 600)
        self.widgetprogressbar = Widget_Progressbar()
        self.widgetprogressbar.show()

        self.widgetprogressbar2 = Widget_Progressbar()
        self.widgetprogressbar2.show()

    def closeEvent(self, event):
        self.widgetprogressbar.close()
        event.accept()

if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    win = MainWindowHide()
    sys.exit(app.exec_())