You must have appropriate permissions to see the navigation for the Roles & Permissions feature. If your organization isn't configured for Self-Service Analytics, you won't see these permissions.
For more information, see Roles.
General Permissions
Self-Service Insights Access
Enables users to create new journeys, delete or rename journeys, and view results. The view permission allows users to see and navigate to the feature page from the menu and see the contents of the page. This is a foundation permission that may be included with higher-level permissions. The admin permission allows users to create new journeys, delete or rename journeys and view results.