if I understand correctly, then all you want is actually to link the two tables by the respondent's ID, but not show it on the GUI. Right?
Well, you can keep that off the GUI and use for ex. the AutoNumber() function on that field in the script to construct an alternative key that you can use to link those tables. Then you can throw out that field altogether.
It depends of course on how the users will access your app. Do they go via their Browser or do they have the Client installed?
Thanks for your quick response. All the fields are in the same table (see attachment) but still we can't filter on one question connected to another. Maybe it's very easy but we are not experienced at all and can not make it work
num(autonumber(Subfield(Question,' - ',1))&'.'&AutoNumber(Subfield(Question,' - ',2))) AS FullQuestionID,
AutoNumber(Question) as QuestionID,
Subfield(Question,' - ',1) AS MajorQuestion,
Subfield(Question,' - ',2) AS MinorQuestion,