When the user wants to create a custom rule in PCM, then we need to develop corresponding BP in B2BI system.
The values given in PCM rules will be placed in the particular workflow in B2BI where we use the rule.
These values can we fetched from the workflow ProcessData and can be used in the custom business process.
Process data is data related to a business process that accumulates, according to configured instructions in the BPML, in an XML document during the life of the process.
If you are entering a value in PCM rule, according to the sequence the values will be stored in ProcessData.
From the above screenshot, value1 is FilePreFix rule parameter, this value will be in the below XPATH.
Same like that goes for Value2, Value3, etc,.
Please find the below URLs for the BPML tutorial PDF.