Thanks. As far as I remember the only times that Firsov and Kharlamov were on the ice together was during powerplays at the 1969 WHC. In that tournament Firsov often played on the point during the powerplays which meant that Kharlamov and Firsov could be on the ice together. Here are some examples of when Firsov and Kharlamov combined on the powerplay.
Here Firsov, Kharlamov and Maltsev combines and almost scores on the powerplay.
http://www.youtube.com/watch?v=MPFE1Q-r0hI&t=104m44s
During this powerplay shift Firsov and Kharlamov combines with each other a couple of times.
http://www.youtube.com/watch?v=28mLLsfVM8E&t=9m24s
Here they also combine a couple of times on the powerplay.
http://www.youtube.com/watch?v=MPFE1Q-r0hI&t=69m15s
Note: Kharlamov was wearing number 12 during the 1969 WHC.
Firsov and Kharlamov were also linemates during one season (71/72) when Firsov played center on a line with Kharlamov at LW and Vikulov at RW. That line was the highest scoring line in the Soviet League that year as they combined for 78 goals. They were also the most productive line at the 1972 Olympics where they also only were on the ice for 1 goal against during the entire tournament. Unfortunately it does not exist much footage of that line playing together as far as I know.