In Procore, users are uniquely identified by their email address and not their first or last names. It's also important to remember that each email can only be associated with a single company within a Procore account. So, if a user has access to multiple Procore accounts and he/she is using the same email address to log in to Procore, that user's email address can belong to Company A in Account 1 and Company B in Account 2. However, a user's email address cannot belong to Company A and B in Account 1.
Therefore, if a person needs to belong to multiple companies within the same Procore account, the person will need to use different email addresses for each company association. (e.g. email@example.com and firstname.lastname@example.org)