There are 4 factions here, so to speak:
1) The Linderman Group: This includes the Hatian, the shapeshifter, Hiro's Dad, Peter's Mom, Nikki, and now Nathan. Parkman is/was in their group in the future episode. HRG left this group after claire was "outed"
2) The Good Guys: Peter, Hiro, Suresh, and Ando.
3) The HRG group: This is HRG, The radioactive caveman, The israeli, and Parkman (in the present)
4) Sylar.
Claire moves along all of these groups. DL/Micah don't belong to any of them, and Nikki may be moving into the Good guys after the abduction of Micah.
The Hatian seems to have directionality to his power, as well as a field of protection.