How to validate the data entry based on previous entered data in the same form

If you have an issue with a specific project please provide the project name in advance. Thank you!

How to validate the data entry based on previously entered data in the same form and also, if we want to validate the entry of the Q3 question based on the addition of Q1 and Q2?

Could you please provide an example?

This is not possible as there is not any question addition feature in Epicollect5, but it could be done in the post-processing using Excel or similar