Method 1: Import the original model into C4D, and realize model mirroring in C4D.
Model mirror method of C4D:
1. Put the object to be mirrored under the command shown below.
Method 2: Import with 3Ds.
Method 3: In rhinoceros, the parts that cannot be exported are blown into groups and introduced into DXF. Because this format is based on color, it is recommended to make it.