Print out two of these brackets and print a spool rod however you like depending on your preferred spacing. The default OD for the spool rod holder is 15.88mm (0.625"). I printed these in PETG with an Elegoo Neptune 3 Pro. I am in the middle of reprinting using a carbon fiber PETG to provide a post for a stronger bracket capable of holding up to 5 kg spools. Have not tested as is with standard Bambu PETG yet. Feel free to add a post for your printer if you beat me to it :). 

I hung these up with 2" long drywall screws though I would suggest adding a drywall anchor unless spacing with studs. holes are counter sunk for flush screws.