Use multiple Group state aggregation functions of same type - for example multiple `OR`

Setup, Configuration and Use Items & Sitemaps
4

Yup, easily use a rule for this.

You can create a group gThermostats and add all those items as members. Then trigger on member-of-group. It’s more efficient than filtering by tags.

Then rule could look like this (done in JRuby)

ORDER = %w[none cool heat]

rule "Update global thermostat summary" do
  changed gThermostats.members
  run do |event|
    summary = event.group.members
                   .map(&:state)
                   .compact
                   .map(&:to_s)
                   .max { |a, b| ORDER.index(a) <=> ORDER.index(b) }
    event.group.update(summary)
  end
end