2 data validation in 1 cell

Hi,

I'm currently stuck on my formula for this project. So, I have to cells that both already have a drop down list. What I want to happen is when you choose from the drop down of Cell A, Cell B will be disable. For example:

in Cell A the list is: Cat, Dog, Mouse
in Cell B the list is: Cheese, Bone, Apple

If you choose "Cat" in cell A then I want cell B to be disabled or will not allow you to choose from the list.

I tried this data validation formula on cell B but I get the error message "the list source must be a delimited list or reference to single row or column":

=OR($A$2="Cat",COUNTIF($A$2,"")='FINAL PARAMETER'!$B$2:$B$4)

Is there another formula that I can do so that when you choose a certain item on the list the other list will be disabled?

Thank you and have a great day!cats.jpg

Create List1 and List2 and List3 which is blank cell

in Data Validation

Allow: List

=IF(A2="CAT",List3,List2)

assuming A2 is your DV selection