Only two teams had a 100 percent record (won all six of their group stage games) in the Champions League/Europa League/Conference League in the 22/23 season.
Those two sides were Bayern Munich (100% record in the Group of Death in the Champions League) and West Ham United (100% record in Group B of the Conference League)
Bayern let in only two goals in a group that also consisted of Barca, Inter and Viktoria Plzen, and those two goals were against Plzen!
Bayern Munich Group C Champions League table 2022-2023 season
West Ham Group B Conference League Table After Group Stage
No team in the Europa League had a 100% record, but interestingly, Group F had all four teams finish on the same number of points.