Hi Kiran,
I don't see any option to assign a new GL account in the list, I see option to add a new Account group via KDH1.
What is the relationship between KDH3 and SETNODE / SETLEAF or SETCLASS?
If I go and check for that GL account it does appear in the system, but when I go and check in KDH3 transaction that GL account does not appear in the list.
Please let me know if you require some other details from my end that would help you understand my issue.
Thanks.