Sitemap group slider question

i have a question about sitemaps and groups.

i need to controll knx system. In items i have few rolershutters and i want to have somthing like this:
Room: x

in this case if i change the value all rollershutters in this group will have value 50 %
but if i click on the name or icon of item i have details view and can controll items with no relation to groups.
on second view option
in group heder i have a slider where i can controll all elements in group inside (all is visible from behining)

Frame label="Some Sliders" {
   Slider item=myGroup ...
   Slider item=member1 ...
   Slider item=member2 ...