hi muiisal
In your action/schematic, select your extended bicubic surface and copy selected (bottom right) or ctrl-c
If you wanted that copy as a backup just hide it , If you want that new extended bicubic to be applied on another layer, just select the layer and press “apply” at the left of the layer box.
If you want every change you will make on ext-bicibic01 to be applied on ext-bicubic02, go in your animation channel select ext-bicibic01 “copy” , select ext-bicibic02 and press “link”
hope it helps !