Check my availability on a separate organization calendar

Hi,

I have a M365 account with company A and company B.

I am using bookings with company A and can check my availabiity on my associated calendar. However I also want to check my availability on my company B calendar too.

I have shared the calendars but that does not work. I added my company B account as a guest user of company A and assigned that user as a staff member to a service but the company B calendar is not searched for this guest user.

Can you assist please?

Thanks

Phil