ODK2 - Multiple selection filters

I am using multiple select boxes. Can I make a constraint to respond with certain limitation like up to 3 responses?
demogForm.xlsx (18.1 KB)

Try something like this:

Constraint = count-selected(${my_multi_select}) <= 3

Thanks Xiphware,
I am using ODK2.0. When I put this formula to the constraint field and converts it throws the following errors:
Error: Error: missing ) after argument list interpretting formula: count-selected(${dffmlymem}) <= 3 on sheet: survey row: 40 column: constraint


Hi @nsthakuri,

I’m not sure if you already found the answer for this, but just in case, you would want to add the following to your constraint column.

countSelected(data(‘dffmlymem’)) <= 3

This will limit the number of options that can be selected to three or less. demogForm.xlsx (18.2 KB)
I’ve also attached an example.


Thanks @clarice_larson,
This is very helpful for me. It really works.