Select the three dot menu in any chat to access Chat details (Figure 1):
Figure 1 Chat details
From here, you can view chat room information such as the name and creation date, room members, attachments and also any room customizations (Figure 2):
Figure 2 Chat Details
Additionally, you will also be able to see the permissions of the room which dictate which functionality may, or may not be available, for example letting new members browser the entire history of the room (Figure 3):
Figure 3 Permissions