This should be a workflow on the input element. Right click on the input element and “Add Workflow”. Then tell the workflow to Change Thing.
You need a place in your Database for the workflow to save the input.
In my example attachment:
- When the Multiline Input value is changed is the default trigger for the workflow when you “Add Workflow” to an input element
- Choose “Make changes to Thing” and choose which data set to change called “Thing to Change”
- Tell it which field in your Database will house the input information and set it to “This [input element]'s value”
Each time you make a selection you’ll have multiple choices so hit me back if you get lost finding the right one.
Cheers! Good luck!