Ability to change details of multiple sub customers/suppliers at once

At the moment, if you want to change the emails, phone numbers, and contacts of a company, you have to go through every sub category and change them manually, even if there are dozens to a hundred of these sub categories. This is time consuming to do, especially when you need to change multiple details.

One way it could could would be holding down the shift key and selecting all of the things you want to change. Another could be a button on the main branch of the customer/supplier saying 'apply changes to all sub groups' which then does so.

Any company which has sub groups under main companies, such as every order relating to a company (in my case, trucks manufactured) would benefit.