I want to filter a combobox by another combobox

[AlexFDS]

Hi,

I have a Power App with many "ComboBox", 2 of them are "REGIONS" and "CITIES".

I need to filter CITIES by REGIONS, but if REGIONS ComboBox is BLANK, the ComboBox of CITIES doesn't has to be filtered.
Now I can just filter if REGIONS ComboBox is not BLANK. 

But in the moment REGIONS ComboBox is BLANK, the ComboBox of CITIES doesn't show any option.

[Akser]

Hi @AlexFDS,

Could you share the CITIES' formula? The one that works when Region is not empty. 

[Drrickryp · Accepted solution]

@AlexFDS 

Assuming Combobox1's Items are Sort(Distinct(Table, Regions),Result),  Combobox2 should be 

Sort(
    Distinct(
        Filter(
            Table,
            IsBlank(ComboBox1.Selected.Result)||Region = ComboBox1.Selected.Result
        ),
        City
    ),
    Result
)

[AlexFDS]

Thank you so much it worked.

I was trying with if with 2 different collections and something like that but never worked.

Ur GOD.

[Drrickryp]

@AlexFDS 

Please mark it solved so others can find it.