Localising Electric Field

I’m an undergrad student learning Geant4 for my dissertation. I’m struck at localising the electric field for a daughter volume. Currently, I am working with a default electric field that runs all over the mother volume using G4TransportatonManager method.
For magnetic field, localising works fine by defining a pointer and assigning it to a desired logical volume but it doesn’t work for the electric field. I’ve already been through the Geant4/ SLAC documentation.
I’ll be glad if someone could help me through it.
Thanks in advance.