Competencies and skills mapped to a job role are job-specific. This mapping allows competencies and skills to populated on Performance Forms in competency sections.
Job Description Manager
In an Instance in which Job Description Manager (JDM) is enabled, competencies are mapped in legacy Families and Roles. For the mapping, navigate from Action Search to Manage Job Roles.

Job Profile Builder
In an Instance with Job Profile Builder (JPB) enabled, competencies and skills are mapped in the JPB tool. For the mapping, navigate from Action Search to Manage Job Profile Content.

Note
More information can be obtained in the Job Profile Builder Implementation/Administration guides. Or, you can check the course titled SAP SuccessFactors Platform Advanced Academy that covers Job Profile Builder in more detail.