Get Octree node origin from the node directly

Good evening,
let’s say I want for one given octree loop over two layers of nodes and get for the second layer the origin of all the nodes. From the doc it seems it is not possible without querying a point and getting the node corresponding. Right now I have the Nodes but I cannot figure out how to get their nodeInfo as apparently if is captured on the fly.
Am I right and should I go to an other lib or manage my octree myself ?