What is a word for a person with more expertise (in certain field) than an intermediate but less so than an expert?
Depending on the field (and potentially how close to intermediate/expert you want to be), a variety of words are viable:
Exactly what qualifies you to be a journeyman varies from profession to profession (if it is even used within a given profession).
It generally means someone who has completed all their training and is considered proficient without having yet proven their mastery.
Skilled, proficient http://www.synonyms.net/synonym/expert
However I have never seen the need.
novice/beginner, intermediate, expert
are the terms normally used
In many companies, the HR dept. have a rating scale along the line of the following:
Novice => Intermediate => Senior => Expert
In Belgium you often see medior, which is between junior and senior.
It's redundant; if you're neither a junior X nor a senior X, then you're just an X.