Dear srkudai,
I agree that a Brahma Jnani alone can be understood by another Brahma Jnani - as a statement - was made because no
one else can understand his real nature. Of course, yes, for a Brahma Jnani, there no one else, excepting the One Being.
But in practice, when two Jivan muktas live side by side they can understand each other as Brahma Jnani. For example,
Sri Bhagavan and Seshdri Swami, Sorupananda and Tattvaraya. Vasishta and Janaka. Vasishta and Rama.
Arunachala Siva.