You can change the variables used in the From Activity and To Orchestration panes without changing the links between source and destination nodes of a map.
For example, you could have a Map Variables activity that maps the nodes of the varBatchOrder variable to the nodes of the varPurchaseOrder variable as shown in the following figure.
The varBatchOrder variable is based on the BatchOrder XML Schema and the varPurchaseOrder variable is based on the PurchaseOrder XML Schema.
If you wanted another Map Variables activity in your orchestration maps source and destination nodes but you wanted to use a different set of variables. You could copy the original Map Variables activity and then paste the new Map Variables activity into the orchestration and then change the variables used in the map without changing the links of the map.
To replace an original variable used in a map: