Use an Expression Macro lvconf to define expressions and parameters that can be referenced by name in other lvconfs.
Expression: enter a LiveView expression.
Parameters: Click Add to assign a case-sensitive parameter name and default value to each. Since parameters are fulfilled in order, if one parameter is unspecified (using the default), then all parameters after it must also be left unspecified.
Parameters can be specified for a macro. Parameters are embedded into the macro expression by prefixing them with a dollar sign (for example, $myParam). Macros are called with positional parameter specification (for example, myMacro(paramVal)).
The Source tab provides a text-based XML configuration file editor, which is a validating XML editor that is aware of the schema that defines the XML syntax of LiveView configuration files. See Text-Based XML Configuration File Editor for more information.