Group By Location 1 or 2

Hi,
I have a question - Where does this Group by Location 1/2 is coming from?
I guess they are "grouped" by rooms but not sure I understand how the logic works

I have on the configuration page only 3 groups defined. But on the list view on iphone I get a lot of devices that I do not need - some actuators appear twice - once in this self created group and once the ones I created in the plugin config page...