I got BF2Editor to open BFHeroes maps (mostly so I could retrieve lighting color settings to be converted to my BFheroes'42 mod).
Here's the files (they are from the current version of the game. v1.26):
Two things to note:
1. Skydomes don't appear. Probably can be fixed but it's just cosmetic at this point. Sun/Moon flares work though.
2. Turn off particle rendering in the View menu. Failure to do so will result in BF2Editor crashing when viewing the level. (seems most of the ambient effects in BFH crashes the editor). Remember the water fall in that one BF2 map that crashes BF2Editor? Well the fix for that is the same for this.
I won't provide support for these files. All I can say is that they should get BFH maps to show up in BF2Editor.
Just extract the rar file to the mods folder of your BF2 game. (do NOT attempt to actually run the mod in BF2 though! It WILL crash!)