Interesting topic
Speaking of Bourbons...I guess there was a far more speacial case of in-breeding centuries later of King Carlos II...
Though there are some doubts about real paternity in some cases, let's suppose everything below is true:
Figure:
1st Generation:
1. Infants Don Alfonso de Orleáns y de Borbón, Duque de Galliera (1886-1975), and his brother Don Luis (1888-1945).
2nd Generation:
2. Infant Don Antonio de Orleáns y de Borbón, Duque de Galliera, m. his first-cousin
3. Doña Eulalia de Borbón y de Borbón, Infanta of Spain
3rd Generation:
4. Infant Don Antonio, Prince of Orléans and Duke of Montpensier, m. his cousin (daughter of an Antonio's first cousin, etc)
5. Infanta Doña Luisa Fernanda of Spain
6. Don Francisco de Asís, King Consort of Spain, m. his 1st cousin
7. Doña Isabel II, Queen of Spain
4th Gen.:
8. Louis Philippe I, King of the French, m. his many times cousin, but distant though,
9. Maria Amelia di Borbone, Pss of the Two Sicilies
10. Don Fernando VII, King of Spain (son of 1st cousins; 1st cousin of 9.), m. his niece
11. Maria Cristina di Borbone, Pss of the Two Sicilies (daughter of 2nd cousins)
12. Infant Don Francisco de Paula of Spain, Duke of Cadiz (brother of 10.), m. his niece
13. Luisa Antonietta di Borbone, Pss of the Two Sicilies (sister of 11.)
14. = 10.
15. = 11.
The following generations also very in-breed, but you can imagine...