Bambu X1C Side Mount Spool Holder v2 for Filler - Fillament Holder

Start with BC's excellent spool holder mount, add in a touch of BobbyMcWho's simplified back, incorporate Aikano9's adapter for HugoG's wonderful Filler - Filament Holder, add a chamfer to use less support and there you have it. 

All credit goes to the designers of these great mods.