Building a complex regex constraint to match the entry between an entry made in the previous question and the later question

[Kal_Lam]

@finercia_americo, this could be a bit complex but you could do it as outlined in the image shared below:

In the survey tab of your xlsform:

Data entry screen as seen in Enketo: when a wrong entry is made

Data entry screen as seen in Enketo: when a correct entry is made

Data entry screen as seen in Enketo: when a wrong entry is made

Data entry screen as seen in Enketo: when a correct entry is made

Reference xlsform:

Regex.xlsx (10.7 KB)