controller.rb

class ProfilesController < ApplicationController
  
  def index
    
    @tracking_profiles = current_user.tracking_profiles
  
  end
  
end

tracking_profile_decorator.rb

module TrackingProfileDecorator

  def filtered_hourly_stats
    hourly_stats = self.hourly_stats.select do |s|
      date_range.begin < s.time && s.time < date_range.end
    end

    self.attributes.
        merge(self.profile.attributes).
        merge('stats' => Stat.merge(hourly_stats)).
        merge('hourly_stats' => hourly_stats)
  end

end

view.slim

- for profile in @tracking_profiles
  = render 'profile', profile: profile.filtered_hourly_stats