Hi, typing this out from scratch because I keep seeing this pop up and people always miss out the step that makes it able to sync to the printer/cloud/AMS… so:
Close Bambu Studio and force quit Handy App if you use it
Go to
“C:\Users<your user name>\AppData\Roaming\BambuStudio\user<long number>\filament\base” or type %appdata% and browse the rest
Open the .json filament you want to copy to any machine, example, copying an X1 profile to a P1S

Open in notepad and save as in the same folder with the same naming convention but for the p1s (or whatever you’re moving it to)
Soooo essentially the same name as the name of the printer you use in Studio after the @:


3D Jake PLA White @Bambu Lab X1 Carbon 0.4 nozzle.json
Becomes
3D Jake PLA White @Bambu Lab P1S 0.4 nozzle.json
Or
3D Jake PLA White @Bambu Lab P1P 0.4 nozzle.json
or
3D Jake PLA White @Bambu Lab A1 mini 0.4 nozzle.json
Now select all in the file and go to Find and Replace - Multiple Text Online - Tools - Joydeep Deb

Paste it into the top box

Scroll down to line 15 and copy the text between the quotes

scroll down to the first find and replace and paste that text into find 1 and in replace you’re using the same as you put in the file name: Bambu Lab P1S 0.4 nozzle

scroll down and click find and replace

Right click in output data and select all

copy that straight back into your notepad file and save again
One last change, find this section

and replace ANY letter or number from the filament id section keeping the same length and format, so I’m replacing “d” with “f”

Save again
Open up Bambu Studio and open up your custom filaments and find the filament you copied originally (you will have two identical ones now so in this example we’re looking for the original X1 version - important it’s the original one.
click edit
now click add new preset

Like magic you can select your new filament you created oon the new machine

Boom!

Why this is a lot more involved than most examples is this will make your filament unique, retain all your custom settings tied to the other presets (shared info), will sync with the cloud and be backed up and removes the duplicate entries by binding it to the original
You will need to make a new k value setting for the new filament too
Note if you’ve made a custom printer profile as long as you created it based on the default the filament will share cross printer profiles once you bind it in the presets