If Role based security was not enabled for your site (Permissions UI):

Give the user Supervisor rights in Financial Edge database view. 
  1. Log into Financial Edge as a user that has rights to Set up System Security.
  2. In any module select Administration.
  3. Select Set up System Security.
  4. Double-click on the user profile.
  5. Mark the Supervisor rights radio icon on the User Information tab.
  6. Save and Close the user profile.
  7. Select File, Exit and Sign out of Financial Edge to make the change take affect.
Please Note:
At this time we are investigating an issue that may prevent Security from being available for Supervisor users when Role based security has not been enabled.  If Supervisor users do not have access to Security, the page can be manually accessed with the following URL combined with your tenant ID:
https://fenxt.blackbaud.com/controlpanel/security?tenantid=[tenantID]
[tenantID]
will need to be replaced with your Tenant ID found in your FE NXT URL.
This article will be updated once this issue is resolved.

If Role based security was enabled for your site (Permissions UI):

Having supervisor rights in database view does not have an impact. An Organizational Admin must give the user Environmental Admin rights.