How to assign where a submenu has to appear? (left or right to the main menu)

Hi,

when a submenu is opened it's usually automatically derermined where it's shown. Depending on where there is enough space the submenu can appear on the left or right of the main menu. How I can specify in Qt where the submenu should appear? Or where I can set that the submenu should not appear above the main menu?

My problem is shown on the attached picture. The submenu (High/Normal/Low) is shown above the main menu, which doesn't look nice (and there is enough space on the left!). Where such properties of the menu can be set?

Thanks a lot for any help!!