The terminology is a little different in Branch: a Metric is called a Topic. A Dimension is called a Field.
The Default Branch Report
Currently the default report in Funnel offers the following metrics and dimensions:
One source per app
Due to quota limitations, the connection will fail if you have more than one connection in Funnel per Branch app.
It is expected behaviour for data to take some time to download. Reconfiguring or connecting a new data source will not speed up the process.
The Custom Exports endpoint is limited to a maximum of 2 million records for each report and fetching historical data is limited up to 120 days prior to the date of export.