They sought help from a marriage counselor to work through their issues.

counselor 是名词，由动词 counsel（提供建议、咨询）加上后缀 -or（表示"从事某种职业的人"）构成，指"顾问、咨询师"。 marriage counselor 指专门为婚姻关系提供咨询和建议的专业人士，即"婚姻顾问"。