Add multiple widget to QTabWidget Tab

I know this is stupid question, but I was wondering how to add multiple widgets to a QTabWidget Tab? Any help with this would be greatly appreciated.

Widgets can contain other widgets. There's a parent child relationship which can result in a tree of widgets. You add the parent widget to the tab.
Use layouts to arrange the widgets.

ok, I got the parent child thing working great. But how would I use a layout to control them?

Using layouts, nested layouts tutorial.
QLayout class reference (look at "inherited by")

I added the widgets to a QHBoxLayout. But they still look stacked on top of each other in the tab.

I tried to use the QTabWidget setLayout option, but that didn't work out so well for me.

I know I am missing something ridiculously stupid here.

Read through the Tab Dialog Example or in Assistant for inspiration