Figurative rock art in northeast Brazil offers a large collection of human representations. In the region of Morro do Chapéu, in the State of Bahia, many scenes present interacting figures with patterned shapes. In this paper, we present a general method based on networks for the analysis of specific traits in relation to defined variables. Here, morphological attributes are used to investigate the behaviour of those different shapes at the Toca do Pepino, a sandstone rock shelter located on the Ventura River valley. We expose how we built a 2-mode network and analysed centrality measures and partitions. This method allows us to propose an interpretation for this figurative rock art in northeast Brazil as a system of graphic patterns shared by different groups.