What is the case position of «الَّذِي» in «جَاءَ الَّذِي أَبُوهُ قَائِمٌ»?

Relative Nouns — Ṣilah, ʿĀʾid, Forms and Syntax

• Accusative position as object
• Nominative position as subject
• Genitive as possessive
• No syntactic role