Use Extract Surfaces 
to create surface-specific visualizations.
Click on the toolbox
in the visualization toolbar.Select
Extract Surfaces. This will open the tool in the properties panel.Click Edit, then either click on the surfaces you want to extract in the 3D Viewer, or scroll up and select surfaces from the control panel.
Click Done.
Click the check icon to extract the selected surfaces.
Extracted surfaces will appear as objects in the Visualizations section of the control panel and can be recolored with different flow quantities or have other visualizations layered on top of them.