You are welcome Sachar
So if you have data like this "*Belling,Birgitta,Mrs." You notice a pattern that you want all text after second comma .
1. FIND(",",B22) this will find you a position of first comma. with belling brigita its position 9
2. FIND(",",B22,FIND(",",B22)+1 - this will find a position of second comma because it looks for comma in cell B22, but it doesn't start from the beginning but from FIND(",",B22)+1 which is next character after first comma. So the second comma for above example is at position 18
3. LEN(B22) - gives you length of the whole string which is 22.
4. If you make difference 22-18 so formulas in 2 and 3 you get 4 which is the length of string you need . So in function right it will be used as parameter length
I hope it's clear now