How do i use conditional formatting based on date and other cells in excel?

Thanks for your explaination, I would update my reply as following.

According to your description, it seems that you need to get following results. Any misunderstanding, you may tell me.

enter image description here

Highlight cell A with Red:

=IF(WEEKDAY(TODAY(),2)>3,AND(A1<=TODAY()-3,B1&C1=""),AND(A1<=TODAY()-5,B1&C1=""))

Highlight cell A with Yellow:

=IF(WEEKDAY(TODAY(),2)>3,AND(A1<=TODAY()-3,B1<>"",C1=""),AND(A1<=TODAY()-5,B1<>"",C1=""))

=IF(WEEKDAY(TODAY(),2)>3,AND(A1<=TODAY()-3,B1="",C1<>""),AND(A1<=TODAY()-5,B1="",C1<>""))

Please also pay attention to the application range of these formulas.

enter image description here