You can even repurpose the Publish Date Document Property Content Control under the Quick Ports > Document Properties menu. It is a date picker and is already mapped.

This page goes into details on how to do that.

Repeating Data Using Document Property Content Controls and Other Mapped Content Controls

I should have avoided the term 'date' altogether as we are too focused on that.

I'll just rephrase. Instead of date, I want to input a plain text string. I do not want a date picker, or date formatting. Just pure plain text. When I input a text string in a 'box', it will automatically fill all the other 'boxes' in the document. If I then change the text string, it will immediately convert all the other 'boxes' to the new input. As I said just like a spreadsheet.

I will review the links provided to see if it will help with this.

Thank you so much for your input