You mean the Weather Underground [1], Symbionese Liberation Army, and so forth? I'm not sure how commonly "domestic terrorism" was used as a term although it was used. That was a long time ago of course but the violence associated with the Vietnam War etc. is quite well documented.
There were over 450 US domestic terror attacks in 1970. It's relevant today because the context it provides shows how we have been historically safe from attacks on US soil for over 40 years.
The last 20 years of terror hysteria created a false mindset that Americans are at meaningful risk of dying in a terror attack. Trillions have been wasted on infrastructure - that can only be responsibly explained as a tool to nurture and reinforce that mindset.
And of course there are the ever increasing loss of civil liberties, each loss shifting power toward Gov and away from us.
There's still not much on the US domestic terror attacks (100s/yr), during the early 1970s. That one has a vibe, as if no one wants to discuss it.