Checkbox as a question type

Hi everyone. l have opened a case where groups are being registered and a followup form which registers the individuals to various groups and the second follow up form is to track the participation of individuals in these groups. So l want to create a checkbox question which will allow me to mark individuals who participated, l want the names of all individuals who registered to pop up automatically in checkbox format

https://dimagi.atlassian.net/wiki/spaces/commcarepublic/pages/2143946908/Custom+Single+and+Multiple+Answer+Questions

Thank you so much, problem resolved.