Yes it's possible.
Let's say that layer you want to multiply/clone is layer at index 1.
To clone image from this layer to another layer, simply add new layer and assign image from layer #1:
//C++ code, but you can easily translate it to Delphi
ImageEnView->LayersAdd(); // newly added layer becomes current layer (I hope so)
ImageEnView->CurrentLayer->Bitmap->AssignImage(ImageEnView->Layers[1]->Bitmap);