Report Settings in Looker Studio

Edit the report settings

Select File > Report settings, or right-click anywhere on the canvas, then click Report settings

Data source

This will set the default data source for all your component but you can also change the data sources for each component in the DATA tab

Google Analytics measurement ID

To measure report traffic in Google Analytics, you can use both GA4 and Universal Analytics IDs, separate them with a comma.

Google Maps API key

This is only for a report that has high trafficked Google Maps embedded reports. Google allow a max of 30,000 free Google Map load per month. PDF download and email views (Email delivery: automated PDF reports that send to an email address) are also counted in Map load.

With the Google Maps API key, a report creator can load more than 30,000 times without having an error. Each load will count against the API key price tier. Please see the detailed guide from Google here

Custom bookmark links > Enable viewer filters in report link

Enable this to let your report viewers save the report's view settings via a URL. This will allow viewers to bookmark any desired filters to access the same filter applied report via a bookmark in the future. For example, let's say your German report audiences only want to see Germany performance. This feature will allow them to save a bookmark, and they can access it without having to select the country filter for every use.

Default date range: Date Range Dimension

Use this to set a default date range for the entire report. If you want to override this value, you can set a different "Date Range" dimension for an individual component.

Report Filter

Use this to set a filter for the entire report, and it will apply to your all components that share the same data source (or a similar source). If you want to override this value, turn off filter inheritance for a selected component.

Google Analytics segment

You can use all the available Google Analytics Segments here, and this field only appears if you are using Google Analytics as a data source for your report.