This document discusses a new multiscale parameterization and history matching workflow for structured and unstructured grids. At the regional scale, it introduces a novel grid-connectivity-based parameterization that flexibly captures heterogeneity while reducing the number of parameters. At the local scale, it leverages established streamline-based methods to refine preferential flow paths. The workflow iterates between regional and local scales to history match production data in a computationally efficient manner.