Export layer filters from a dwg to another in AutoCAD and Civil 3D

This function is not yet available in AutoCAD plain.

AutoCAD: 
For instance, drawing A is the drawing containing the layer filters. Drawing B is the drawing where you want the layer filters to export to

1. Make a copy of the drawing A
2. Delete in this copy all its entities
3. Do not run purge
4. Copy all the entities from drawing B into drawing A

Civil 3D:

1. Invoke LAYER command
2. From Layer Manager click on Save Filter Group icon
3. Save LFT file
4. Open new drawing and go to Layer manager
5. Click "Load Filter Groups" icon and load LFT file