[Bug/Feature Request] FinOps Hub v13 – Need aggregation by Cost Center instead of Subscription + missing Cost Center sync

Context / Business Need:

We need to customize the Azure FinOps Hub v13 default Power BI report (Storage Account export) so that costs are grouped by Cost Center (project/budget) instead of being grouped by Subscription.
Multiple subscriptions belong to the same project (same budget), so the expected report behavior is:
➡️ One consolidated cost line per Cost Center
➡️ With the ability to drill down into subscriptions and resources

Problem Description

Attempt 1 — Using the custom Azure tag cost_center (tag in subscription +RG +resources)

When we use the tag to group resources in Power BI, there is always a gap between:

The sum of the subscriptions belonging to the project
The sum of the resources filtered by cost_center:project01, for example

Reason:
➡️ Many Azure resources do not support tags by default , so the tag-based filtering never fully matches the subscription totals.

Attempt 2 — Editing the Cost Center directly in Azure (Cost Management + Billing)

We tried updating the Cost Center field in cost and billing directly.
After refreshing FinOps Hub and power bi:

The updated Cost Center value does NOT appear in the tables consumed by the Power BI report
FinOps Hub v13 seems not to ingest or expose this billing Cost Center field
We could not find a way to group by subscription Cost Center, because tags exist only at resource level, not at subscription level in the power bi report default schema (no subscription tags ligne )

This makes it impossible to build a reliable “per Cost Center” view.

Observed Behavior

• Inconsistent results between subscription totals and cost-center-tag-based totals
• Cost Center changes from Azure Cost Management + Billing never show up in the FinOps Hub dataset
• No built‑in way to group costs by subscription → cost center

Steps to Reproduce

Deploy FinOps Hub v13 with Storage Account +power bi report
Tag some resources with centre_de_cout
Compare:

Sum of subscriptions for a project X
Sum of resources using the cost center tag

Edit Cost Center in Azure Cost Management + Billing
Refresh FinOps Hub + Power BI
Observe that:

Cost Center billing fields are not included
Tag-only aggregation creates mismatches

Start with the FinOps Hub v13 Storage Account export and default Power BI report, then compare subscription totals with resources filtered by the cost_center tag. Check whether Azure Cost Management billing Cost Center values are present after a FinOps Hub and Power BI refresh. Done means the report exposes Cost Center values and supports consolidated Cost Center totals with drill-down into subscriptions and resources.