Using Open VDB assets with 3Delight for Houdini requires a geometry node with 3Delight vdbVolume shader assigned to node's material's attribute and inside this geometry node we should place a File node with the corresponding VDB file name that we want on it's Geometry File attribute. (Reference video by Lewis Taylor)
Use the browse button to select a VDB file on the File node.
Once a VDB file has been set, you will have to select and type the proper Smoke, Temperature, Emission Intensity and Velocity grids. The Velocity Scale attribute will be used as a multiplier over the Velocity grid values
Shading an Open VDB volume is done by using the vdbVolume shader node.