Excluding Selection
Add an Excluding Selection subnode () to a Constraint node to exclude selections already added to that node.
The options in the Selection list and Output entities list define the selection that should be excluded. See Specifying Selections for more information. The excluding selection’s options are similar to the selection’s options, except there is no options for a global selection, and the output entities should have a dimension that is lower than the dimension of the selection of the parent Constraint node.