Thank you Phil for that Quick answer.
what I would like to do is to repeat a group of questions, such as a nested field.
For example, for a project describing plants in a sector, one type of plant must identify and characterize. thereafter for the same sector we continue to identify other plants with different caracteristics.
For the moment, I put 20 groups hoping that during the field visit there are not 21 ...
thank you you again for any help