RE: Dynamics 365 (CRM) user security role to manage users
Hi partner,
After a lot of tests, I found that when a user has the privileges for the Security Role, Team and User entity, then he can assign the security role to other users, but can only assign the security roles he already has.
Please refer to this blog: https://community.dynamics.com/crm/b/magnetismsolutionscrmblog/posts/permissions-required-to-manage-roles-in-dynamics-crm-2011
Create a new security role that only gives it Read and Assign permissions to the Security Role entity; Read, Append and Append to privileges for the Team entity and User entity.

Assign this new security role to specific users (or a owner team) so that these users with this security role can assign security roles that they have to other users, and add users to the team.
For example, User A has two security roles, 'Account Manager' and 'Sales Manager'. After you assign the new security role to User A, then he can assign 'Account Manager' and 'Sales Manager' security roles to other users, and he can add any user to any team.
For security roles that User A does not have, he cannot assign them to users.
So, if you want to assign security role B to some users, first you need to assign security role B and new security role to user A, then user A can assign security role B to other users.
In addition, I found a similar theme: https://community.dynamics.com/crm/f/microsoft-dynamics-crm-forum/165688/security-role-permissions-to-create-users-and-assign-security-roles-to-users