As both .nwf and .nwd file originate from NavisWorks, it is likely that only this program is capable of conversion between these formats, if that is actually even possible. Sadly, this information could not be verified, however given the fact that .nwf is a project it may be possible.
Convert NavisWorks project file to NavisWorks snapshot.
We found 2 software records in the database related to .nwf to .nwd file format conversion.
Microsoft Windows software - convert nwf to nwd on Windows
A project review and visualization software
Convert from nwf file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned nwf to nwd. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A 3D design review package for Windows