when I choose my different questions in the preamble group I still can't get access to the group that answers my filters. 

For example in my preamble group I answer :
-yes to question P3, i.e. P3=="Y
-to question P4 I answer well, i.e. P4=="Well
-to question P5 I answer treatment system, i.e. P5=="treatment system". 

So to have access to the group: Waterfront residence with well and individual wastewater system (5293) my answer in the group in the preamble must be P3=="Y" and P4=="Well" and P5=="Treatment system".
This gives as equation: P3 == "Y" AND P4 == "Well" AND P5 == "Treatment system".
The problem is that none of my groups appear. I tried with OR instead of AND there all the groups appear. Then I tried with OR first and AND second all the groups that are about the waterfront residences show up. Then I tried P3 == "Y" AND P4.NAOK == "Well" AND P5.NAOK == "Treatment system" nothing is displayed either. 
What is missing? What should I change? 

Translated with www.DeepL.com/Translator (free version)

Hi,

And here again is your mistake
P3 == "Y" AND P4 == "Well" AND P5 == "Treatment system"

Neither "Well" nor "Treatment system" are answer option codes but answer option text.
Remember: The text may be different if there are different languages, but the code is the same.

You have to use the answer option codes.
Which are in P4 "A1" or "A2", in P5 "PR6" and "PR7"

So the above equatoion should be
P3 == "Y" AND P4 == "A2" AND P5 == "PR7"

I corrected your equations in the first two groups.

 

Joffm

 

Finally, it's working! Thank you Joffm for your help and patience!
I understood that you could create filters with the answers or codes. And when we used the codes we didn't have to put quotation marks but for the answers we did. I just understood that only with numbers you don't have to put quotation marks and that the link is always with the code that has to be written in quotation marks because it is in text.