I have a class Graph with two lists types namely nodes and edges

I have a function

List<int> GetNodesInRange(Graph graph, int Range)

when I get these parameters I need an algorithm that will go through the graph and return the list of nodes only as deep (the level) as the range. The algorithm should be able to accommodate large number of nodes and large ranges.

Atop this, should I use a similar function

List<int> GetNodesInRange(Graph graph, int Range, int selected)

I want to be able to search outwards from it, to the number of nodes outwards (range) specified.

So in the first function, I expect it to return the nodes placed in the blue box. The other function, if I pass the nodes as in the graph with a range of 1 and it starts at node 5, I want it to return the list of nodes that satisfy this criteria (placed in the orange box)