You can move on to the next node by clicking the green arrow in the navigation bar at the bottom of the node you are in. To the right is the next node. To the left is the hub where you are. Once you are done working with all the nodes around the hub, only the hub symbol remains. You then click on it to move along to the next hub, if you like navigating like this. You can also get to the next node by clicking it directly in the map.