This will only work if each of the horizontal layers in your diagram are identical.
If so then you can save the trained model parameters:
torch.save(simple_model.state_dict(), "path/to/file.pth")

and then load them into each of the horizontal layers:
filepath = "path/to/file.pth"

complex_model = [network() for i in range(num_layers)]

for layer in complex_model:
    layer.load_state_dict( torch.load( filepath ))

where network is the model you originally trained.