The phrase "same elevator" means that two or more people are on the same level or have the same understanding or knowledge about something. It is a way of saying that they are on the same page or have similar opinions or experiences. Full definition
During past internships and while doing interviews, I ended up in the same elevator as Anderson Cooper and Shonda Rhimes. (cnbc.com)
Sitting in an open plan office, eating lunch in the kitchen and riding the same elevator as a colleague will help develop open communication, transparency and trust, each an integral characteristic of a strong culture. (entrepreneur.com)
For example: if we're at work and I don't know you and we both get into the same elevator and I either say «good morning» politely or ignore you totally — I don't want a kiss. (datinggoddess.com)