Found the answer on the tweet thread:
Youtube link: https://www.youtube.com/watch?v=60XZ3k85IWE&feature=emb_logo starts at 17:12
The english translation of the verse 8 from Book 7
This one was really difficult. Most of the traditional commentators have said that this verse refers to those studying Taittiriya Shakha.
But Kataka's commentary mentions that Kausalya had an independent Purohita by name Tittiri Maharshi. So, Taittiriya refers to his group and not the vedic shakha.
"तित्तिरिमहर्षिः कौसल्यायाः प्रत्येकपुरोहितः"