Yes, this can be done by utilizing the Multi-Tenant Support. This feature enables you to grant another Bitmovin account access to your own Bitmovin account. If they don't have an Bitmovin account yet, they have to sign up first.
You can add their new Bitmovin account to a so called “group” in your "Team" configuration overview. A Group is a collection of access rights that is applied to all members of the group. It allows you to control which resources (Encoding, Player, Analytics, Account) those users can see / create / edit / delete in your account. Once that is done, these users can switch to your account by selecting it in the upper right menu.
The only settings that can’t be accessed this way are the billing settings of your account. Those can be viewed/changed by your account only. However, you can allow other users to access the invoices of your account, if you want to.