Stefan,
Maybe I'm not explaining my problem well. All the endnotes (for three different sections) are already at the end of the entire document. I don't want the endnotes to appear at the end of each SECTION. I want them all at the end of the book, appearing continuously. They all appear correctly now.

In the footnote / Endnote dialogue box, there is no option called "Location" (maybe because I'm on a Mac). But I do get an option to place them either at the end of the section or at the end of the document. But as I explained above, I do not want them to appear at the end of each section.

Is there no way to have all the endnotes appear at the end of the DOCUMENT, and then to place the Glossary and Index BEHIND the notes?

I don't know what "right click endnote text" means. What am I right-clicking on?