playback skipp

Hello there.. I need a help.. Im a gamer... Actually i saw some of streamer they make live stemming but i can't trim while the live stemming. I couldn’t go back to see his 1/2 minute. There was no trining sing. How to they do that? I want to do same thing... If you know this setting please...

this is the playback help when I play the game its fine but when I go back to look at the video its lagging and skipping badly I went to other forums and none seemed to work I also put log files