Thank you for your response!
Yes, something along those lines.
If you look at the attached picture - what I want to do is to create a bar for "all lighting devices" and stack the remaining categories on top of it. So there would be 173 On/Off Switches, 3 Dimming lighting devices, 25 Energy Meters and so on. Basically, each function should be counted separately.
Can you provide the sample workbook?