From Serious Sam Wiki
Graph control is used to edit values of graph data in property group panels.
Graph control has two operations:
1. Graph button
- The graph button is located left of the down arrow button on the right side of the value field. Clicking it opens the Graph Dialog where graph data can be edited further.
2. Down arrow button
- Clicking the down arrow button on the right side of the value field opens the dropdown menu on the right.
- This menu lets you select a graph processing type. For more information see Graph Dialog.