Dropdown label parameter dependent on another dropdown label

[asaleem.cem19]

I'm creating a light family. There are different lights, all having different configurations of their own. What I want is that if the user selects 'Light A' from the dropdown, the next dropdown should show different configurations of Light A only, and not all the configurations of all the lights.

The following is just an example of the process I need

First drop-down:

Showing all the countries of the world

Second  drop-down:

Showing all the States of the country selected in the first drop-down

Third drop-down:

Showing all the cities in the state selected in the second drop-down.

The above example was just to make my point easier to understand. 

Is there any way to achieve that?

[Simon_Weel]

What do you mean with 'Drop down'? Can you post a screen shot?

[asaleem.cem19]

By drop-down, I mean the label parameters we set on nested families.

Following are two screenshots

[Simon_Weel]

The Family Type parameter / selector. Don't think you can make it work as you describe - Revit Formulas don't do string operations, which you most certainly would need to accomplish your goal. 

[asaleem.cem19]

So is there no way to add some formulas like (If "United States", Alaska, California, Florida, ...etc)

So if a user selects the United States, the second label parameter filters out the results to show only the American States.

[Simon_Weel]

Sadly, no - formulas lack a lot of functionality. I'm sure it must be possible with Dynamo, but that's a whole different thing.