Currently, it seems local graph shows the note (node 0) and its direct links (node 0->1). It would be powerful if one could incrementally extend the locality. For example, show all notes linked to node 0 and node 1 (node 0 → 1 → 2). Of course, decrement to revert closer to original node 0.
Tie a hotkey to it, like cmd-plus and cmd-minus
It is possible already with the graph settings.