For more information about render nodes and connections, see About shading networks.
To show connections
Input and output connections are sometimes called upstream/downstream connections.
Displays the input or upstream connections of the selected node. This option graphs the network up to the input(s) of the selected node.
Displays the output or downstream connections of the selected node. This option graphs the network from the output(s) of the selected node.
Displays both the input and output connections of the selected node.