I am running the ETL job to passing the database username,pssswd positional arguments to shell script (bash) and how can we suppress/hide the password from ps command.
The ps output is not your problem. The problem is that you are passing a cleartext password through a publicly viewable channel.
Instead of passing the password to a process through a command-line argument, pass it through a pipe, pass it through a regular file with restricted access permissions, pass it through a shared memory segment with restricted access permission, ...
Can you share the commands you are using for the three stages (or combination) so we can suggest improvements. Otherwise we're just guessing.
Robin