To Export Geometry to an OBJ File

Open the model to be exported.
Select File > Export > 3D Modeling File Types > OBJ (*.obj) .
The OBJ Export Settings dialog opens.
Adjust settings as required.
Click Export.
The Create OBJ File dialog opens. The default file name is that of the DGN file, but with a *.obj extension.
Use controls in the dialog to select a folder and, optionally, change the file name.
Click Save.