Select Attribute-to-script to display Attribute-from-script connection - Settings so that you can create an attribute-to-script.

An attribute-to-script appears in the Composition Editor as a double-headed arrow pointing toward the edge of the free-form surface.

A script connection is a connection between a part represented visually within the Composition Editor and code available to the composite part you are working on. Script connections provide a way to implement functions that are not provided by any of the parts of the application, but belong to the application as a whole.

If you select More dependencies, you can specify other attributes as additional dependencies. Changes to the other attributes trigger the evaluation of the connection to yield an up-to-date value for the attribute.