unist-util-flatmap offers a utility function for transforming a unist (universal syntax tree) node by mapping it to a list of nodes. It traverses the tree, applying a provided function to each node. This function can either return a single node, an array of nodes, or nothing (effectively removing the node). unist-util-flatmap simplifies tree manipulation by providing a concise and efficient method for restructuring unist trees based on node-specific criteria.