Hi talal,
Among various approaches, the following may be the simplest way. Could you please try?
1) Click inside the plot frame of the inset source graph to show the layer frame (yellow
box with green handles), and press CTRL-C key to copy the layer.
2) In the destination graph, press CTRL-V key to paste. It creates the additional layer.
You can move/resize this layer to let it appear as an inset.
Note that you can link the layers from the Plot Details dialog, if you like.
Hope this works.
--Hideo Fujii
OriginLab