Struggling to see layers from vtk export of Flexpde solution

Hi everyone, i am using flexPDE to solve thermal profiles across refractory layers. i am generating a VTK file using the TRANSFER function and I am importing this file into Paraview. I am trying to visualise this solution in Paraview however the geometry is a solid block and I cannot view the different refractory layers. I need help to resolve this as it is important to understand in which refractory layer a certain isotherm is located. Appreciate your assistance on this thank you.

Solid paraview geometry- no layer lines

FlexPDE view showing different layers of material