//MyMainWindow.cpp
void MyMainWindow::OnThisButtonClick (TObject *Sender)
{
    workManager::ActivateSomething();
}

//WorkManager.cpp
void WorkManager::ActivateSomething()
{
    if (currentTab < 0)
        return;
    workersArray.GetItem(currentTab)->DoSomething();
}

//Worker.cpp
void Worker::DoSomething()
{
    ParallelWorker::StartTask();
}

//ParallelWorker.cpp
void ParallelWorker::StartTask()
{
    //DOING ACTUAL WORK
}

void ParallelWorker::ParallelWorker(SomeKindOfParent &parentContainer)
{
    CtrlLayout(myLayout);
    parentContainer.AddUnit(myLayout);
    myLayout.thisButton <<= THISBACK(StartTask);
}

void ParallelWorker::StartTask()
{
    //DOING ACTUAL WORK
}