Re: "made for iphone cochlear dont move from one device to another : If cochlear is paired with iPhone and want to play anything on MacBook it shows incomplete pairing and when then pair with MacBook (M4) it shows incomplete pairing in iPhone. Tired with error . Same goes with ipad (M4)."
Am no expert in this area, your hearing professional may be the best person to advise. Yet your question to the community deserves some response.
Wondering whether your cochlear implant is "Made for iPhone" (Mfi) compatible with any of the Mac computers, or whether compatibility does not extend to your Mac.
Apple support's online article: List of Made for iPhone hearing devices - Apple Support
Eg lists the following models:

Models listed above are compatible with iPhone, and iPhone's software can assist in controlling them,
Models not listed will likely rely on bluetooth conncion, and maybe a Cochlear app / firmware for control.
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As the above article explains:
As none of the above models has an asterisk after the model name, it seems no Cochlear models "use bidirectional streaming, which allows you to talk hands-free" on the listed compatible Mac computers.
MFi hearing devices without an asterisk use unidirectional streaming. Some Macs are Mfi compatible.
Unfortunately, seems MacBook (M4) is not one of the listed Mfi compatible computers :
nearest compatible models include:
MacBook Pro introduced in 2021 or later using macOS Sequoia 15 or later
MacBook Air introduced in 2022 or later using macOS Sequoia 15 or later
Sorry to say it seems unlikely you will be able to switch your Cochlear implants seamlessly between iPhone and MacBook (M4) as things stand. I could be wrong.
Tips for using Mfi hearing devices with iPhone or iPad:
Use Made for iPhone hearing devices - Apple Support
Eg: Also: says about Mac controls:
In System settings > Accessibility > Hearing Devices " (Hearing Devices appears only
if your Mac and macOS are compatible with MFi hearing devices.)"
and
"If your hearing device has its own app from the manufacturer, that app might offer additional settings and controls".