Selecting a node by clicking it dims the other nodes so that you can more easily see the arrows to and from the highlighted node.
It also enables you to move the selected nodes as a group within the visualization.
Selecting a node by clicking it does not filter the data in any way.
To select a single node
Click the node to select it and highlight the arrows pointing to and away from the node.
To add another node or group of nodes to your selection
To remove a node or group of nodes from your selection