I can add " primary sub-menu" and their executable...

HOW do I add another "primary sub-menu" ?

All in code -
I have given up on adding menus in QTDesigner GUI - too inconsistent...

This is what I am after

mdiArea "bar ' main menu
primary submenu secodary executable
secodary executable
secodary executable

another primary submenu secodary executable
secodary executable
secodary executable

QMenu *BT_Menu_SubMenu = menuBar()->addMenu(tr("&Bluetooth bluetoothctl (command)... "))
->addMenu("&bluetoothctl submenu ... ");

this adds to main menu bar - not what is needed

QMenu *BT_Menu_SubMenu_1 = menuBar()->addMenu(tr("&Bluetooth bluetoothctl (command)... "))
->addMenu("&bluetoothctl submenu ... ");

int sub_Index = 10;
QAction *aboutAct_submenu_index_0 =
    BT_Menu_SubMenu->addAction(tr("& bluetoothctl  help "),
                             this, [this, sub_Index ]()->void{menu_slot_indexed(sub_Index);});
sub_Index = 11;
QAction *aboutAct_submenu_index_1 =
    BT_Menu_SubMenu->addAction(tr("&bluetoothctl  list adapters..."),
                               this, [this, sub_Index ]()->void{menu_slot_indexed(sub_Index);});