That approach is a quite unreliable way of hiding content in a document. It does not, in fact expand/collapse anything. All it does is to toggle the font's hidden state for the bookmarked range. Whether it actually works depends on how the user has Word configured. If the user has Word configured to show hidden text (which is what most users who can see Word's formatting marks would have) or, even if the text does hide, whether that text gets printed, is entirely beyond the macro's control - it all depends on Word's configuration.
In answer to your question, though, yes, you'd need a separate macro for each MACROBUTTON field. A single macro could handle multiple bookmarked ranges, though.
To conditionally expand/collapse a document, you really need to control what is in it, not the font properties. See, for example:
https://www.msofficeforums.com/word-...html#post60848
https://www.msofficeforums.com/word-...own-lists.html
https://www.msofficeforums.com/word-...own-field.html