Good day,

The process originator's name gets stored as part of the workflow context. When you assign the destination of the first activity browse to the Originator field on the workflow context browser and select the manager field under the Originator (when expanded).

As part of the activity, add a data event that will save the name of the ActivityInstanceDestination to a process-level data field (Also part of the workflow context under the Activity Instance section).

When assigning the second activity's destination, look up the manager field of the previous user by making use of the ADUser SmartObject, using the stored username in the data field as an input.

Hope this makes sense!