I have created a page for my app which is for user management - what I am trying to achieve is the creation of a new user and their company being set from the current users company.
I.E the user creating the new user is from company a.
When the new user is created I want to set the value in the company field on their user record as company a, the same as the user who just created them.
You should use the Create account for someone else action. Sign up signs the user up and sets it as current user as well (as far as I have experienced).