Though, as per screen-shot I found that you are trying to add the selected values from pop-up in the property with column seperation? If yes, you can use Map Structure along-with data transfrom as explained in the above link.
Also, you can take hints and implementation details of somewhat similar functionality of dragging the selected rows/tuples from UI Gallery.
DesignerStudio -> User Interface -> UI Gallery -> Row Action-> Click Actions. You can view the design configuration by clicking on link above the right side panel "View design time configuration".
Kindly notify and mark the reply with "Answered/Helpful", if it helped you or give you an idea.