You can create XML Path (XPath) expressions in Workbench.
XPath expressions are used in processes to identify data items in
the process data model, such as data stored in process variables.
For example, the XPath expression /process_data/@id identifies
the id node in the process data model.
When this expression is evaluated at run time, it returns the
data that the id node represents, which is the
identification number for the process instance.
Expressions can include paths to data nodes, as well as functions
and operators that act on the data:
In processes, you can use XPath expressions to specify values
for operation properties, values in configuration dialog boxes for
events, and values in routing conditions. You can use XPath Builder
to create expressions, or you can enter them manually. When you
create XPath expressions manually, ensure that you use the same
case as the variables you reference. Variables are case sensitive
in Workbench.
For information about XPath, go to www.w3.org/TR/xpath in
your web browser.