When you want to use the same data for different purposes, you can link the port providing that data to multiple ports in the mapping.
You can create a one to many link in the following ways:
Link one port to multiple transformations or output objects.
Link multiple ports in one transformation to multiple transformations or output objects.
For example, you want to use salary information to calculate the average salary in a bank branch through the Aggregator transformation. You can use the same information in an Expression transformation configured to calculate the monthly pay of each employee.