Overall, I want to display an index map that shows nautical charts and their corresponding inset charts. The majority of the time these insets lay directly on top of the "parent" chart in a given location. I want to be able to illustrate to clients that within this parent chart, they will also receive the inset chart. In our systems current status, I need to make this work with a multipart polygon. Is there a union or similar tool that allows something like this? In the picture, red outline = inset chart and purple = parent chart.