Five other men have already been arrested after the incident at the car park on Perry Hill Road, in Oldbury, on Sunday, July 3.
A 21-year-old man suffered a deep cut to his chest after disorder broke out at around 1.10am.
The force has said that it wants to speak to five other men about the disorder and has published CCTV images of the men to help find out if anyone has any information about them.
A spokesman for West Midlands Police said: "We want to speak to these five men about an assault on a car park on Perry Hill Road, Oldbury, in the early hours of Sunday (3 July).
"A 21-year-old man suffered a deep cut to his chest after disorder broke out on the car park around 1.10am.
"We arrested five men in connection with the incident. We now want to speak to these five further men about the disorder.
"Recognise any of them? Or think you can help the case?
"Get in touch via Live Chat at http://west-midlands.police.uk quoting crime number 20/608532/22."