When a user comments on a user competency we can not determine if they were in a plan, in a course, or potentially else where. Therefore the sent to other users notifying of a new comment can not produce a reliable link to the user competency... checking all the courses may be expensive, the competency may not be in a user plan.

Create a page that shows the information about that user_competency, possibly including all the plans it is in, and all the courses with that competency the users is enrolled in.

The links in the messages sent should then point to the user competency page, not the plan or course any more.