Compound graphs are often useful for modeling components of hierarchical systems. While node-link diagrams can be used to visualize these graphs, adjacency matrices have the advantage of eliminating occlusion between edges, even in dense networks. However, matrices do not reveal the hierarchy in a compound graph. To address this issue, we propose a novel hybrid visualization technique that combines an adjacency matrix with treemaps displaying portions of the hierarchy. A prototype is presented that illustrates these ideas and supports visualization of digraphs with weighted edges. Interaction techniques allow the user to reorganize the hierarchical groupings of elements and facilitates the exploration of links within the network. For example, in software engineering, the prototype enables browsing of links between source code modules to help discover the architecture of the software.