Wenceslaus I, Duke of Luxembourg
Wenceslaus I( also" WenceslasVenceslasWenzel", or" Václav", often called Wenceslaus of Bohemia in chronicles)( 25 February 1337 – 7 December 1383) was the first Duke of Luxembourg from 1354.
He was the son of John the Blind, King of Bohemia, and Beatrice of Bourbon.
Blanche of Bourbon
Blanche of Bourbon( 1339 – 1361) was Queen of Castile as the wife of King Peter.
She was one of the daughters of Peter I, Duke of Bourbon and Isabella of Valois.
Mary of Avesnes
Marie of Hainaut (1280–1354) was the daughter of John II, Count of Holland and Philippa of Luxembourg, her brother was William I, Count of Hainaut.
Sophia of Bavaria
Sophia of Bavaria (1376 – 4 November 1428) was a Queen of Bohemia and the spouse of Wenceslaus, King of Bohemia and King of the Romans.
She was briefly interim regent of Bohemia after the death of Wenceslaus in 1419.
Beatrice of Bourbon, Queen of Bohemia
Beatrice of Bourbon (1320 – 23 December 1383) was a French noblewoman.
A member of the House of Bourbon, she was by marriage Queen of Bohemia and Countess of Luxembourg.
She was the youngest daughter of Louis I, Duke of Bourbon, and Mary of Avesnes.
Beatrice of Bohemia
Beatrice of Bohemia( 1225–1290) was a daughter of King Wenceslaus I of Bohemia and his wife Kunigunde of Hohenstaufen.
She married Margrave Otto III and was the mother of:
Beatrice of Naples
Beatrice of Naples( 16 November 1457 – 23 September 1508), also known as Beatrice of Aragon, was twice Queen of Hungary and of Bohemia by marriage to Matthias Corvinus and Vladislaus II.
She was the daughter of Ferdinand I of Naples and Isabella of Clermont.
Mathilde of Bourbon
Mathilde of Bourbon( – 18 June 1228) was a French noblewoman who was the ruling Lady of Bourbon from 1171 until her death.
Margaret of Bohemia, Duchess of Bavaria
Margaret of Bohemia( 1313–1341) was the daughter of King John of Bohemia by his first wife Elisabeth of Bohemia( 1292–1330).
Anne of Bohemia (1290–1313)
Anne of Bohemia( 1290 –1313) was the eldest surviving daughter of Wenceslaus II of Bohemia and Poland and his first wife Judith of Habsburg.
Her siblings included Elisabeth of Bohemia and Wenceslaus III of Bohemia.

Question: Who is Beatrice Of Bourbon, Queen Of Bohemia's maternal grandfather?
Answer: John II