JohnAziz FYI I found what I was looking for if anyone else is curious. The docs talk about doing document level scoping for security purposes via Azure AD Groups here: https://learn.microsoft.com/en-us/azure/ai-services/openai/concepts/use-your-data?tabs=ai-search#document-level-access-control
You can modify that "Filter" property in the json body to use other OData queries, in my case something like this to limit to a subset of documents in the index by ID
"filter": "id eq 'aHR0cHM6Ly9hcmNoaWVzdG9yYWdlLmJsb2IuY29yZS53aW5kb3dzLm5ldC9pbmRleHRlc3RyYW5kb20vZGF0YS9YM1RBTUZNV0MzWFBYVlZORVZRVkVLUldIN05EREVTTi5wZGY1' or id eq 'aHR0cHM6Ly9hcmNoaWVzdG9yYWdlLmJsb2IuY29yZS53aW5kb3dzLm5ldC9pbmRleHRlc3RyYW5kb20vZGF0YS9YM1RBTUZNV0MzWFBYVlZORVZRVkVLUldIN05EREVTTi5wZGY2' or id eq 'aHR0cHM6Ly9hcmNoaWVzdG9yYWdlLmJsb2IuY29yZS53aW5kb3dzLm5ldC9pbmRleHRlc3RyYW5kb20vZGF0YS9YM1RBTUZNV0MzWFBYVlZORVZRVkVLUldIN05EREVTTi5wZGY3'"