Context:
The goal of this spike is to explore options to allow user defined handling of complex/object variables during data import.

Also see https://docs.google.com/document/d/1FEv2tYn1dZ4rUBqULu0FYPT4yyJbNzEf1hbz11JT_EQ/edit for more details on where this feature idea is leading.

Grouping by complex variable: 

Potentially display the typeahead within the menu.