Copy Activities between projects having different WBS

if there is a baseline attached then you can go to Maintian Baselines and select Update

from here you can tell it what you wabt updated check the second section where it says Add new activities and activity data 

Uncheck update exiting activities already in the baseline 

then select Update options and select General Activity information 

activity code assignments 

relationships

WBS assignmnets and anything else listed

then select Update 

you will receive a message Update process complete

check your results 

Have you opened both projects at the same time? You can then Group by WBS or any common Activity codes they may share.

I haven't explained the case well, I opened both projects, the activities in both share the same activity IDs, names etc.. (minus a few exclusions). The difference is that the WBS where these activities are stored under.

For example

Project (Old) : Activity 1 is under WBS 1.1.1

Project (New) : Activity 1 is under WBS 1.2.1.1

The problem is that There are many activities like this stranded accross multiple WBS. (I can filter them in the activities tab).

Since I'm still developping the Baseline, no BL is attached yet.

Hi Hamza,

Probably you could try a quick verification on your side using the Update Baseline feature as suggested by Zoltan and see what happens (make a backup of your draft baseline first). 

The baseline to attach is basically your master baseline draft.

Open both projects 

make sure that you are in the WBS folder then copy activites from 1 project to the other