My advice to your PO or stakeholder would be to not do this since the user is already able to overwrite the value just by double clicking on the text field. The trash-icon will only take up extra space, create alignment issues, be different to normal Mendix-apps and you will have to prevent unwanted behavior.
Having said that, there is no widget yet doing this yet. To get this done:
let current = document.querySelector('.current');
let prevSibling = currentNode.previousElementSibling;
and set the value of prevSibling to null.
If you feel upto it: create a widget yourself doing just this.