Use Azure Devops API to retrieve a list of changes in an Azure DevOps pipeline

I have an unusual situation for using the Azure DevOps API to run reports about pipelines. I am running a pipeline In Azure DevOps with two different repos. The ‘self’ repo contains YML and the ‘other’ repo contains Java application code. Using two repos isolates the pipeline changes from app code changes.

Here’s an example of a successful run. The repo sources are listed at the bottom of the screen shot. The YML_files repo is the ‘self’ repo used by the pipeline. The Java repo is referenced as a source during the pipeline’s run.

After a successful pipeline run, I can see the changes for both repos in the Changes page as shown below.

Here is the problem: Using the API, I can retrieve all changes in the current build for the Current Pipeline (aka the ‘self’ repo) because they are linked to the build ID and there is a pre-built API query for that. However, I am unable to identify the changes in the Java repo. Using the run details query, I can find id of the Jave repo and also identify the head commit 1547fd41… But I can’t get the other changes listed below 1547fd41. Does anyone have a solution?