A common question from Excel users is along the lines of; I have a list in a cell that has used Data-Validation with the "List" option. I would like to have another cell display a list that is depended on the item chosen in my first list.
There are quite a few ways to achieve this, but the easiest by far is using the INDIRECT functions in the validation. The INDIRECT Function return the reference returned by a text string.
Here is your guide on how to add dependent data validations in excel
You will find a refresher course to data validations and two possible ways to add dependent data validations in excel.