Understand path names
If two objects in a scene have different parents, they can have the same object name. If you refer to an attribute of such an object in an expression, you must use a more complete name that includes the object’s path name.
An object’s path name has this format:
pathname|objectname.attributename
where pathname is the parent node’s name, objectname is the object’s name, and attributename is the attribute’s name of the attribute.
A vertical bar ( | ) symbol divides the pathname from the object name. Don’t type spaces before or after the | symbol.
For example, a scene might have a child of GroupA named Ball.tx and a different child of GroupB named Ball.tx. If you write this statement:
Ball.tx = time;
Maya generates an error because it doesn’t know which Ball.tx to set.
To eliminate the error, you must enter the pathname of the attribute as in this example:
GroupA|Ball.tx = time;
The | symbol between GroupA and Ball.tx indicates that the object to the left of the symbol is the parent of the object to its right. Use no spaces before or after the | symbol.
The Expression Editor displays pathnames for such objects. For example, the Objects list displays GroupA|Ball.