Yes, great-grandfather was grandfather's father. His great-grandfather was his great-grandfather's father, which was also his grandfather's father.
Han Gaozu's father was Liu Zhijia, also known as Liu Taigong.
Gaozu's father called him Tianzu. It was mentioned in Erya Shiqin: " Those who gave birth to themselves are their parents, their father is their grandfather, their grandfather's father is their great-grandfather, their great-grandfather's father is their great-grandfather, and their great-grandfather's father is their great-grandfather." Therefore, Gaozu's father was called the Heavenly Ancestor.
Liu Bang's father was called the Heavenly Ancestor.
Liu Bang's father's name was Liu Taigong.
Liu Gaozu's father was called Liu Wei.
Liu Bang's father was called Liu Taigong, and some people called him Liu Wei.
Emperor Gaozu's father was called Liu Taigong.
His father, Emperor Gaozu of the Han Dynasty, had a reading list that included the following chapters: Chapter 001: This Child Doesn't Look Like Me at All, Chapter 002: The Prince Next Door, Chapter 003: The Big Rascal, the Small Rascal, Chapter 004: How to Be a qualified King of a Dukedom, Chapter 005: Respect Between Brothers, Chapter 006: Family Banquet, Chapter 007: Singer Liu Bang, Who Is the Compositor? Chapter 008: My Unreliable Brothers, Chapter 009: House Demolition Demon, Chapter 010: The Warm and Kind Uncle, Chapter 011: The Greatest Man, Chapter 012: The King of Benevolence, Chapter 013: Whirlpool, Chapter 014: Protector of the Great Han Dynasty Dukes, Chapter 015: Shang Fang, Chapter 016: Marquis Wuyang, Chapter 017: Three Wishes, Chapter 018: A New Storm, Chapter 019: Various Discussions, Chapter 020: Human Tragedy What Strange Thing Did You Get Into?