Yes, this is possible if you have the username or password (given we are talking about users within your company), or you can also utilize the 'link account' feature for this as well.
Linked accounts (or single sign-on), can be used to connect users or admins within the same company account OR you can use that for separate companies.
For Example: If I have 2 company accounts, I would link my accounts for a single sign-on/linked account. However, as they are different companies and I have different databases and lead lists, there are separate metered charges because of a separate account.