The dataviewer has now 2 panels: "Current" and "Watch"
The "Current" panel should have a filter for "Fields" , "Global" (vars) and "Local" (vars)
The user should also be able to add "Watch" panels that can be freely named
AND in all formula-entry panels it should be possible to select variables from any of the watch-panels
The need for some native way to parse multiple variables maybe would be much less.