This leaks memory: every time the button is pressed, a new menu is created. The old one isn't deleted. It should be enough to create the menu in the constructor and set it on the button. You will also need a a destructor, to delete the menu:

DlgBundleManager::~DlgBundleManager()
{

delete(m_ui->m_importResources->menu());

}

Check the documentation of QPushButton: http://doc.qt.io/qt-5/qpushbutton.html#setMenu