Currently prompted variables do not allow a user to be able to select multiple items from a given list. The drop-down allows single selection from a list of values and checkbox returns a single value depending on whether it is checked or not. I am using the multi-line input as an workaround but this means user needs to add/delete lines to reflect their selection which is a poor approximation and error prone as well.
Thanks for getting in touch! It’s not currently possible in prompted variables to allow multiple items from a list to be selected. There aren’t any current plans to implement this enhancement either, unfortunately. I’d recommend suggesting this idea up on our UserVoice site, which is the main avenue we consult when considering features and enhancements like this for future versions, and to prioritize it based on community support.
Thanks. Unfortunately it is bad news trying to post via uservoice too:
You’ve used all your votes and won’t be able to post a new idea, but you can still search and comment on existing ideas.
There are two ways to get more votes:
When an admin closes an idea you've voted on, you'll get your votes back from that idea.
You can remove your votes from an open idea you support.
To see ideas you have already voted on, select the "My feedback" filter and select "My open ideas".
I guess I’ll just give up on this and continue using my workaround.