Kindly refer to the following link(s):
Combining intentions while fasting
Combining intentions of missed days of Ramadan with Mondays, Thursdays, white days, Ashura, Arafah
Can we combine multiple intentions in a form of worship (fasting or prayers....)?
Double intention for missed fasts with Ashura Arafat 3 White days Mondays Thursdays?
Fasting missed days of Ramadan with Mondays & Thursdays, 3 white days, Arafah, Ashura