Reply To: Modifying field values for neighboring cells inside a postprocessor
No, this is not intended as all individual threads of a kernel always only process cells of the same block (all LBM processing is split into per block operators). You should be able to handle the cuboid number / cell ID mapping at the same place where you perform the inter block communication of your algorithm.
However, in principle nothing prevents you from passing the cuboid number as a block-specific parameter to your operator (with application scope PerCellWithParameters)