Is possible to get kdb delta and collaboration documents associated with d

I'm a little unclear on what you mean here. Could you explain kdb "delta"? Do you mean change in size over time? Specifically for the collaboration kdb?
And what do you mean by "add data to another kdb"? It's not possible to manually add any data to kdb files.

Let say there are 2 appian environments A and B, B was created based A, by migrating data from A to B. Users did some work on A after migration, now A is different from B.
How I can A and B to be same without going thru full migration, meaning that can I get only difference between A and B, then migrate that difference to B.

I don't believe that's possible, and it's not something we would recommend trying. Going through the full migration would be best.