eshell-subcommand-bindings

eshell-subcommand-bindings is a variable defined in `esh-cmd.el'.
Its value is

((eshell-in-subcommand-p t)
 (default-directory default-directory)
 (process-environment
  (eshell-copy-environment)))

Documentation:
A list of `let' bindings for subcommand environments.

You can customize this variable.