There is a way, but not very straightforward. From your team screen, click the red button that reads LUXランキング (Lux ranking) right above the class display (Sクラス, Aクラス, Bクラス, or Cクラス). After that, click the second tab. Your team is highlighted in red, and it reflects your standing as per last 4am JST.
But that's not all. To find out where your team really is, you need to trace from the very top. Count how many of your union medals you see until you reach your team, and the number is your true team rank. I don't know if there's an easier way of doing this, sorry!