How to use value in cell after filtering data, using data validation list method

how can i get a value in cell after selecting criteria from coloum type1, type2, type3, using data validation list method. also list value behave like filtering, only m,n value should be list in type 2 if I select a in type1

type1 type2 type3 Value
a m o 21
a n p 22
b m q 23
b n o 24
c m p
c n q

type1 type2 type3 Value
List a m o 21 "=21x some function.

Thanks for your valuable time.