When Toneri Otsutsuki sees Urashiki he greets him with formality and respect. Implying that Toneri knew that he is superior to him. But Toneri’s respects do not seem to bother Urashiki as he didn’t seem to care. It also seems that Urashiki and Toneri have met before and known each other already.
From the movie, we know that Toneri Otsutsukitsutsuki thought that he was the last living Ōtsutsuki and the same thing to Urashiki Otsutsuki. But Urashiki clears his misconception and tells him that the main family of Ōtsutsuki clan still exists and is thriving. It also seems that even Urashiki has superiors and thus there can be numerous Otsutsuki clan members. Toneri was confused at the idea that more of his kind existed. He doesn’t get why his own family would watch him, and his clan suffer. Urashiki acknowledges saying ‘they saw it all’. Then he goes on to describe the events of the last movie, which is where we were introduced to Toneri.