Is there a safe and official way to give your account to a relation firm (and choose exactly what they can and can not do with it if possible)? Just handing a p

Is there a safe and official way to give your account to a relation firm (and choose exactly what they can and can not do with it if possible)? Just handing a password from my Facebook/Google/whatever account to someone else doesn't sound good. Many people even use their accounts to log-in to everything and run their whole life and business so a leak can be catastrophic.