It may be possible that *.bdy files can be somehow converted to *.nam file using the program from which both of these file originate, the DMAP lora distribution mapping program. No other BDY to NAM conversion is known to us.
Convert DMAP boundary file to DMAP spreadsheet file.
We found one software available in the database for this conversion.
Microsoft Windows software - convert bdy to nam on Windows
A flora distribution mapping program for Windows
Convert from bdy file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.