Final answer:
The 30-year-old sales manager is trying to achieve self-actualization, which is the highest level in Maslow's hierarchy of needs, representing the fulfillment of one's full potential.
Step-by-step explanation:
The 30-year-old sales manager expressing a desire for a job change because they feel they are not living up to their potential is seeking to achieve self-actualization. According to Maslow's hierarchy of needs, self-actualization represents the fulfillment of one's full potential and sits at the top of the pyramid. It is the stage where individuals aim to realize their abilities, and it occurs after physiological needs, safety and security, love and belonging, and esteem needs have been met.