Specifies the optional level of the node. A lot of graph charts, such as org charts and flow charts, are not just scattered about the chart surface. There is a definite organization, e.g., things flow from a top to a bottom (or a left to a right) and many nodes are considered equivalent so they are placed at the same level as other nodes. The Level property is an integer property from 0 to whatever specifying the level of the node. This Level property is used by the Arrange method to divide the chart canvas into a big grid, where each cell in the grid can contain one chart value. One axis of this virtual grid will be the Levels in the chart. The other axis will be all the nodes/values at that level.
The following code creates a graph chart value and initializes its Level. Then, it creates two children (e.g., Level+1) of the first graph chart value: