How to set a new window into a GroupBox in QT?

Question

I have a Window with a Group Box called Function control box

I want to include this window into that group box

I do that by using this code

ui->functionControlBoxGroupBox->setParent(componentIdentification);

Where componentIdentification in an UI object of the window above.

But it seems that nothing happens. Why?

This is what happening. From this:

To this:

Question:

How can I import a complete window form into a group box in QT?