As I said before, the hyperlinks do not seem to work if they are in the
result text of an IF field. (here, it does not seem to matter whether you
are linked to a data source or not).
Presumably you are not actually merging the document - if you do, you lose
the bookmarks so the hyperlink won't work anyway. So maybe you are just
previewing.
Hyperlinks do work if they come from an INCLUDETEXTed document. As long as
your ETHERNET field can only take specific values (say "Y", "N" or "" ) then
you can exploit this by
a. creating a document (let's call it mytexts.doc) that contains each of
the texts you need, including hyperlinks that reference the correct bookmark
b. bookmarking the texts BMY, BMN and BM
c. using { INCLUDETEXT "the full path name of mytexts.doc" { MERGEFIELD
ETHERNET } } to insert the bookmarked texts
You may have to select and re-execute the INCLUDETEXT fields before they
will work properly, especially if you use
{ HYPERLINK "{ FILENAME }" \l "bookmarkname" } within mytexts.doc to avoid
hard-coding the including document name.
This approach has another problem in that you rely on the linked .doc file -
you can't use ctrl-shift-F9 to remove the INCLUDETEXT without also
destroying the hyperlink.