Is there a anything like this out there?

Apologies in advance for the poor picture ...

Trying to find out if this can be done with any type of software? Seems to me this is a very specific action that would require some serious coding on some word processor or operating system. Word 2016 master document seems to do the complete opposite. InDesign kind of does it (master pages) but only within one file and not several. In my head (THIS) would be the title of a section and would be a similar to when you place an image into a InDesign file. Once you change (THIS) to THAT in the original file it would change in all the others.

Hope this makes sense.

Cheers