How to Filter Power Apps Gallery with Multi-Select Combo Box (Delegation Workaround)

Filtering a gallery based on multiple selections from a Combo Box is a common requirement in Power Apps. However, when using SharePoint lists as a data source, you often encounter Delegation Warnings that prevent the app from processing large datasets correctly.

In this guide, I will demonstrate how to implement multi-select filtering for both SharePoint (with a workaround for delegation) and Dataverse.

Preparation: Data Sources & Test Setup

First, let’s look at the data sources.
1. SharePoint List (Target Data)

2. Dataverse Table (Target Data)

How to Test Delegation

For more details on delegation limits, check out this article:
Power Apps Delegation and Row Limits Explained

Case 1: SharePoint List (The Workaround)

The In operator is NOT delegable with SharePoint. If you use the simple formula below, you will receive a delegation warning, and it won’t work for large lists.

The Solution: Hard-coding Index Values

To avoid delegation issues, we need to compare each selected item individually using the Index function.

Note: This method limits the number of filterable items (e.g., users can only select up to 3 items in the Combo Box).

// Replace 'SampleList' with your SharePoint List name
// Replace 'ComboBox1' with your Combo Box control name
// Replace 'Title' with the column name you want to filter by

Filter(SampleList As item,
    // 1. Show all if nothing is selected
    IsBlank(ComboBox1.SelectedItems) || IsEmpty(ComboBox1.SelectedItems) ||
    
    // 2. Filter by 1st selected item
    (CountRows(ComboBox1.SelectedItems) > 0 && item.Title = Index(ComboBox1.SelectedItems,1).Value) ||
    
    // 3. Filter by 2nd selected item (if exists)
    (CountRows(ComboBox1.SelectedItems) > 1 && item.Title = Index(ComboBox1.SelectedItems,2).Value) ||
    
    // 4. Filter by 3rd selected item (if exists)
    (CountRows(ComboBox1.SelectedItems) > 2 && item.Title = Index(ComboBox1.SelectedItems,3).Value)
)

Important: Do not use Index directly without checking CountRows. If you try to access Index 1 when 0 items are selected, Power Apps will throw an internal error.

Case 2: Dataverse (The Recommended Way)

If you use Dataverse, the In operator IS delegable. You can use a much simpler formula without any item limits.

// Replace 'SampleTable' with your Dataverse Table name
// Replace 'ComboBox1_1' with your Combo Box control name
// Replace 'Name' and 'Title' with your column names

Filter(SampleTable, 
    // Show all if nothing selected, otherwise check if Name is 'In' the selected items
    IsBlank(ComboBox1_1.SelectedItems) || IsEmpty(ComboBox1_1.SelectedItems) || 
    Name in ComboBox1_1.SelectedItems.Title
)

This is one of the major advantages of using Dataverse over SharePoint for large datasets.

Bonus: Filtering with Lookup Columns

What if your Combo Box choices come from a Master Table (Lookup)?

For SharePoint:
You need to compare the ID of the Lookup column.

For Dataverse:
It remains simple. Just ensure you are referencing the correct column in the In clause.

Related Articles

• Power Apps Delegation and Row Limits Explained
• Basic Gallery Filtering Techniques