This is a sample script for retrieving the values of dropdown list of the smart chips on Google Document using Google Apps Script.
At August 23, 2021, 3 Classes for retrieving the smart chips have been added to Google Apps Script. But, in the current stage, unfortunately, all values of the smart chips cannot be retrieved by the Classes. For example, the dropdown list of the smart chips cannot be retrieved
Incredibly useful report and workaround from Kanshi Tanaike for Google Workspace Devs needing to get some ‘smart chips’ values from Google Docs. Hopefully classes/methods will be added to Apps Script and the Google Docs API (here is a related feature request you can star in the issue tracker), particularly as the current solution is to convert the Google Doc to .docx and then back to Google Doc.