These are all the Links that lead into your selected Node. In code, this highlighting is performed by:
Node node = myDiagram.SelectedPart as Node; if (node != null) { foreach (Link link in node.LinksInto) // For that Node, get LinksInto, cast all as ((NavModelLinkData)(link.Data)).Highlight = 1; // NavModelLinkData, and set Highlight to true }
All the Links leading into the SelectedNode are obtained by the LinksInto property. Then we get each Link's data and set its Highlight property to 1, as any Link is 1 "relationship" or "step" from the Node it connects with.