Hi,
If you are loading hierarchies from BW to BPC dimension, you can achieve it by having a default value in transformation file.
"Note : There is no hierarchy load to ABC object in BW only MD and TXT load is done."
What do you mean by this sentence. You are not loading hierarchies from BW? Then how are you updating hierarchies?
Even if you are not loading from BW, one solution would be to start new load and have the default value in conversion file.
Thanks,
Manohar