BI Dashboards are made for your company's needs, so it's difficult to provide a help guide that will cover the queries that get asked without being specific to your organisation.
If your company is using custom fields you may need assistance from the support team to identify or include these fields in your reports.

For any questions or queries with BI reports, contact us with details of what you need or are trying to do, so we can review and advise further.

Example of a Power BI Dashboard embedded in Hydra: