Learn how to create cascading dropdowns in Power Apps with multi-level, searchable, and offline-ready examples. Complete end-to-end guide with formulas, tips, and best practices.

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✨ Introduction

Cascading dropdowns are essential for building dynamic, interactive forms in Power Apps. They allow hierarchical selections where one dropdown determines the options in the next.

Example Scenarios:

• Country → State → City
• Product Category → Product → Sub-Product

In this tutorial, we’ll cover:

• Multi-level cascading dropdowns
• Searchable combo boxes
• Offline-friendly collections
• Dynamic defaults and conditional formatting

By the end, you’ll have a fully functional cascading dropdown system in Power Apps.

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1️⃣ What Are Cascading Dropdowns?

Cascading dropdowns filter options in one dropdown based on the selection in another.

Real-world Example:

Country	State	City
USA	NY	New York
USA	CA	Los Angeles
India	MH	Mumbai

💡 Tip: Cascading dropdowns prevent invalid selections and improve user experience.

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2️⃣ End-to-End Example: Country → State → City

Step 1: Prepare the Data Source

1. Create a SharePoint list Locations with columns: Country, State, City.
2. Populate it with hierarchical data (as above).
3. Ensure there are no blanks or duplicates.

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Step 2: Load Data into a Collection (Offline-Friendly)

In your app’s OnStart property, add:

ClearCollect(colLocations, Locations)

💡 Tip: Collections improve performance and enable offline usage.

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Step 3: Create the Country Dropdown

1. Insert a Combo Box control → rename cmbCountry.
2. Set Items property:

Distinct(colLocations, Country)

3. Set DisplayFields: ["Result"]
4. Enable Searchable for easier selection.

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Step 4: Create the State Dropdown

1. Insert Combo Box → rename cmbState.
2. Set Items property:

Distinct(
    Filter(
        colLocations, 
        Country = cmbCountry.Selected.Result
    ),
    State
)

3. Enable Searchable
4. Disable until a country is selected:

cmbState.Disabled = IsBlank(cmbCountry.Selected.Result)

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Step 5: Create the City Dropdown

1. Insert Combo Box → rename cmbCity.
2. Set Items property:

Distinct(
    Filter(colLocations, State = cmbState.Selected.Result),
    City
)

3. Enable Searchable
4. Disable until a state is selected:

cmbCity.Disabled = IsBlank(cmbState.Selected.Result)

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Step 6: Optional – Default Selections

cmbState.DefaultSelectedItems = LookUp(colLocations, Country = cmbCountry.Selected.Result, State)
cmbCity.DefaultSelectedItems = LookUp(colLocations, State = cmbState.Selected.Result, City)

💡 Tip: Defaults guide users and reduce errors.

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Step 7: Test Your App

1. Run the app.
2. Select a Country → State → City.
3. Child dropdowns update dynamically.
4. Use the search boxes for fast selection.

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3️⃣ Advanced Features & Tips

3.1 Searchable Dropdowns

• Use Combo Box instead of Dropdown for large datasets.
• Enable Searchable property for type-ahead filtering.

✅ Benefits: Faster selection, better UX.

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3.2 Multi-Level Cascading Dropdowns

For complex hierarchies (e.g., Country → State → City → Area), extend the logic:

// State
Distinct(
    Filter(
        colLocations, 
        Country = cmbCountry.Selected.Result
    ), 
    State
)

// City
Distinct(
    Filter(
        colLocations, 
        State = cmbState.Selected.Result
    ), 
    City
)

// Area
Distinct(
    Filter(
        colLocations, 
        City = cmbCity.Selected.Result
    ), 
    Area
)

💡 Tip: Always disable child dropdowns until the parent selection is made.

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3.3 Using Collections for Offline Apps

• Load data in a collection on app start.
• Use the collection for dropdowns to improve performance and allow offline usage.

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3.4 Conditional Formatting & Dynamic UX

• Disable child dropdowns until the parent is selected:

cmbState.Disabled = IsBlank(cmbCountry.Selected.Result)
cmbCity.Disabled = IsBlank(cmbState.Selected.Result)

• Highlight missing selections with border color:

BorderColor = If(
                  IsBlank(
                      cmbState.Selected.Result
                  ), 
                  Red, 
                  Gray
              )

• Use LookUp for dynamic default values.

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3.5 Performance Tips

• Use Distinct() to remove duplicates.
• Limit records with FirstN() if needed.
• Use delegable data sources (Dataverse, SQL) for >2,000 records.
• Prefer collections for offline or repeated filtering.

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4️⃣ Common Issues & Fixes

❌ Issue	✅ Fix
Child dropdown not updating	Use .Selected.Result or .Selected.Value
Large datasets slow	Use collections or delegable sources
Blank or incorrect defaults	Validate parent selection and use LookUp()

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5️⃣ Quick Reference Formulas

Dropdown	Items Formula
Country	Distinct(colLocations, Country)
State	Distinct(Filter(colLocations, Country = cmbCountry.Selected.Result), State)
City	Distinct(Filter(colLocations, State = cmbState.Selected.Result), City)
Disabled Logic	cmbState.Disabled = IsBlank(cmbCountry.Selected.Result)