Moving data element from stage A to stage B in tracker program

Using DHIS 2 for case based surveillance with tracker program and 2 stages.
In stage A, data elements includes demographic information and clinical information.
In stage B, newly created to detailed information.
I have tried to move some data elements from stage A to stage B, but the fields did not get the values already entered while in stage A.
Please advise

Please elaborate About the data elements before moving and how you want it to look after moving.