Power Platform Community Forum Thread Details

Hi Community,

I have a scenario involving N:N relationships and need some advice:

I have an ABC entity that has a 1:N relationship with Contact.
The ABC entity also has an N:N relationship with the XYZ entity.
Additionally, the XYZ entity has a 1:N relationship with Contact.

Now, when I use the “Add Existing” option to associate XYZ records with ABC, I want the lookup to only display those records that are linked to the same Contact associated with the ABC record.

Is there a recommended way to filter the lookup this way? Any references or advice would be greatly appreciated!

Categories:

Microsoft Dataverse with Power Apps

@Muzammil Nawaz

hanks for the detailed scenario—this is a common challenge when working with N:N relationships in model-driven Power Apps or Dynamics 365.

To summarize your setup:

ABC (custom entity) has:
- A 1:N relationship with Contact.
- An N:N relationship with XYZ (custom entity).
XYZ also has a 1:N relationship with Contact.
You want the “Add Existing XYZ” lookup on ABC to only show XYZ records linked to the same Contact as the one associated with the ABC record.

✅ Recommended Approach

To filter the lookup in the “Add Existing” dialog, you’ll need to use a custom JavaScript web resource with a custom filter on the lookup field. Unfortunately, out-of-the-box filtering for N:N lookups in the “Add Existing” subgrid is limited, but here’s how you can approach it:

🔧 Option 1: Use a Custom Lookup + JavaScript Filtering

Replace the N:N subgrid with a custom lookup field (or a custom subgrid with a button to launch a filtered lookup).
Use JavaScript to filter the lookup based on the Contact associated with the current ABC record.

Here’s a simplified example of how the JavaScript might look:

function filterXYZLookup(executionContext) {

var formContext = executionContext.getFormContext();

var contactId = formContext.getAttribute("your_contact_field").getValue();

if (contactId) {

var lookupControl = formContext.getControl("your_xyz_lookup_field");

lookupControl.addPreSearch(function () {

lookupControl.addCustomFilter(

`<filter>

</filter>`,

"xyz"

);

});

}

You’d register this function on the OnLoad event of the form and possibly on the OnChange of the Contact field.

🔧 Option 2: Use a Custom Dialog or PCF Control

If you want to keep the N:N relationship but need more control over the selection process:

Create a custom command button on the subgrid using the Ribbon Workbench.
Launch a custom dialog (e.g., using a Canvas App or a custom page) that:
- Filters XYZ records based on the Contact.
- Allows selection.
- Creates the N:N association programmatically using Web API.