Sometimes graphs can be too large to fit onto the screen at once. In this case, it is useful to be able to search the graph for any nodes you are interested in. There are two commands which let you do this.
Choose Edit > Find... to find any node in the graph whose name contains a given string. Choose Edit > Find Next to find the next node in the graph that contains that string. Whenever a matching node is found, it is selected in the graph. If necessary, the window scrolls so that the selected node is visible.
Note that you do not have to specify a complete node name: to find all nodes that include the word "debug" in their name, just type
debug
into the dialog. All searches are case insensitive.
A full description of these commands can be found in Searching for text and objects.