Direct bvh to dxf conversion is unlikely because of the different type of content, but export of the 3D geometry to 2D DXF format should be doable with any 3D modeling tool that supports such a 3D to 2D export function.
BVH format is designed for storing character animations, for example, motion capture data, so exporting that type of content to DXF is a bit odd. Still, a 2D view of the 3D meshes is probably doable with Blender or similar software.