What you are describing is known single-sourcing using conditional text. The regular technical writing software packages do exactly this (such as Madcap Flare) but Word is not known for this ability.
However, it can certainly be done in Word and wouldn't necessarily take as long as Charles predicted. It does require some highish level skills in Word programming though.
The basic steps are:
- You need to tag every 'chunk' of the document with bookmarks.
- Then you build a userform that presents a listbox of all the bookmarks which can be selected
- The macro then hides all of the non-selected chunks and shows all of the selected chunks
- Update the TOC and output to PDF
The trick would be structuring your document and organising your bookmarks so that any chunks can be shown or hidden without leaving holes in the heading structure. It is possible to overlap different bookmarks so IF you do this, the macro that shows/hides the content will need to do the hiding first and then the showing second.
FWIW, I wouldn't be looking at doing this in MS Access unless you were looking to make this far more complicated.