Refers to a person who studies or practices law; can be an academic legal scholar, a jurist, or a lawyer. In academic contexts, it often means a professor or researcher of law.
He is a famous legal scholar and an expert on constitutional law.
To become a legal scholar, you need to study law in graduate school.
法律家 is a broader term for a legal professional, including judges, prosecutors, and lawyers, whereas 法学者 emphasizes scholarly or academic expertise.
Compound of 法 (ほう, 'law') + 学者 (がくしゃ, 'scholar'). The reading ほうがくしゃ follows standard on'yomi readings for the kanji.