Form example:

Select a state and only cities for that state will show.

 

 

 

 

 

Create the Master List:

 

 

 

 

Create the Source List for, Add the Data

 

 

 

 

Customize the master list in Power Apps.
Change the State and City cards to drop-downs

 

 

 

 

Bring in the Source List connection in

unlock fields

 

 

 

 

 

Set the values for the state,  get the state from the source list datasource

 

 

 

 

 

Set the value for City, match the State value selected with the State in the datasource

 

 

 

 

 

Set State card Update property from
DataCardValue.Selected.Value to DataCardValue.Selected.Result

 

 

 

 

 

Set State card Update property from DataCardValue.Selected.Value

to DataCardValue.Selected.Country

 

 

 

 

 

 

 

 

 

Save and Publish.