There used to be something like this, but it no longer exists. There was a barrier between NG and NG+. People in NG could only summon and invade people who were also in NG, and anyone in NG+ could summon anyone else in any NG+ cycle (NG+2, NG+3, etc.), but not people in regular NG. They removed the barrier a while ago though, so now someone in NG can summon someone in NG+5 as long as they were in the same soul memory bracket. I think the main reason they removed the barrier was because people who died a lot had a really high SM whilst still in NG, so they couldn't summon anyone because no-one in NG was in that area at their SM.