So were you part of a team which sought to capture a flag and bring it back to a home base (which means it was a CTF map)? Or was the object of the game to work in a team and just kill members of the opposing team (so a TDM game)?
Have you tried all those maps whose names you listed? If you don't have them in your cache, have you tried to download them from a site like https://unrealarchive.org/?
PS - Having just briefly played them, I can say it's not any of these going by your description and screenshot
DM-CampersRevenge.unr
DM--{ISC}--oriental-passage-3E.unr
DM-A-Helicopterwar-Echo.unr
DM-CMNstreetDD.unr