Power BI Custom Connector

Hi  KeyurPatel14 

The requirements can be handled using the standard Power Query custom connector patterns, although there are some UI limitations.

• Filter dropdown: You can expose predefined filter values through a connector function parameter using Documentation.AllowedValues. This allows Power Query to present the values as a selection list, and the selected value can then be used to construct the OData $filter query. However, custom connectors don't provide a general framework for creating arbitrary UI controls.
  Back/re-selection: Custom connectors don't expose an API to add a custom Back button or control the Navigator's navigation flow. The recommended approach is to return a Navigation Table containing the available entities/tables. Users can then select the required entity from the Navigator rather than restarting the connection.

  Useful Links : https://learn.microsoft.com/en-us/power-query/handling-navigation-tables

  https://learn.microsoft.com/en-us/power-query/handling-resource-path

  https://learn.microsoft.com/en-us/power-query/samples-directory

   

  Hope this helps !!

  Thank You.

Hi KeyurPatel14​,

The Community Support answer covers the main pattern, but I would make one distinction between predefined and dynamically discovered values.

For a known set of filter values, Documentation.AllowedValues is a good fit. Microsoft's function documentation guidance confirms that providing Documentation.AllowedValues changes the normal parameter textbox into a dropdown, so you can take the selected value and use it when constructing your OData $filter.

If the choices themselves need to be retrieved dynamically from the API, I would look at a dynamic navigation table instead.

Microsoft's navigation table guidance supports nested and dynamically generated navigation tables. That lets you model something like:

Filter/category → entity → table

inside the normal Navigator experience.

That also gives you a cleaner answer to the Back/re-selection requirement. Custom connectors don't expose a general UI framework for creating your own Back button or multi-step wizard, but nested navigation tables let the Power Query Navigator handle moving between levels and selecting a different entity.

One thing to watch with dynamic navigation is evaluation. Microsoft notes that navigation nodes are lazy by default, so I would build the tree so API calls happen only as the relevant node is expanded/selected rather than loading every entity up front.

So I would use:

• predefined values → Documentation.AllowedValues
• API-driven/dynamic choices → dynamic navigation table
• multi-step selection → nested navigation tables

That keeps the connector within the Power Query UI patterns rather than trying to build a separate custom interface.

Hi KeyurPatel14​ 

We wanted to follow up to check if you’ve had an opportunity to review the previous responses. If you require further assistance, please don’t hesitate to let us know.