I do not believe it is possible to achieve what you are looking for.
You can just ignore and not accept the changes at stream B, for the changes coming in from stream A.
Both repository workspace and streams work in the same way and is bidirectional.
Comments
Dr. Hans-Joachim Pross
JAZZ DEVELOPER Nov 22 '13, 10:02 a.m.Rainy John
Nov 22 '13, 5:18 a.m.