When you create a new Relations constraint, it is automatically added to the operator’s My Macros node. Every relation is a Macro that can be renamed and used in another relation. You can add inputs and outputs to your Macro by selecting operators found in the Macro Tools node.
When you drag a Macro relation into another relation, a dialog box appears asking if you want to create the relation as a Sender, Receiver, or a Macro.
Select Macro to create a Relations constraint box that has both Sender and Receiver inputs and outputs, select Sender to create the Relations constraint box as a Sender that transmits data, or select Receiver to create the Relations constraint box as a Receiver that is influenced by the data transmitted from the Sender.
Macro constraint A. A Relations constraint named “Arm Macro” B. “Arm Macro” used as a Macro in the Relations pane.
The Macro becomes a single relation, representing the entire set of constraints within that Macro; all the Input-Output Relations constraints used in your Macro become connectors on that relation.