11.3. Filters Live in Data Sources
In Looker Studio, filters are an essential part of data sources. They allow you to control and manipulate the data displayed in your charts and tables. In this lesson, you'll learn where filters live, how they are associated with data sources, and the concept of filter scopes and inheritance.
Filters and Data Sources
Filters are linked to the data source applied to a chart. To illustrate this, let's use an example. We have a chart with the data source from a Google Sheet, and we want to apply a filter for "revenue more than 220". However, if we have another chart in our report with a different data source, such as Google Analytics, the same filter will not work on this chart because the field "revenue" is different in both data sources.
To apply a filter to a different data source, you need to recreate the filter specifically for that data source. You can do this by going to the chart's settings, selecting the data tab, and choosing the data source. When you create a filter within the settings of a table, the filter will be associated with the data source applied to that table.
For example, we have a Google Analytics data source and we create a filter called "revenue_ga greater than 220". This filter will work on the chart with Google Analytics data source because it is specifically created for that data source.
Filter Scopes and Inheritance
Filters can be applied at different levels in Looker Studio: chart, page, and report level. These levels define the scope and inheritance of filters.
Report Level Filters
Report level filters are applied to the entire report. They affect all charts connected to the same data source. To apply a filter at the report level, go to File > Report Settings, select the data source, and then create a filter. The filter will apply to all charts with the specified data source.
Example: You have a report for email marketing and you want to filter out all non-email traffic. You can apply a report level filter for "source medium equals email".
Page Level Filters
Page level filters are applied to all charts on a specific page connected to the same data source. To apply a filter at the page level, right-click on an empty area of the page and select "Current Page Settings" or go to Page > Current Page Settings. Just like report level filters, you can add filters that affect all charts on the page with the specified data source.
Example: You create a page to analyze traffic from different source mediums. You duplicate the page and apply different source medium filters on each page (e.g., Google CPC on one page, email on another page).
Chart Level Filters
Chart level filters are applied to a specific chart only. They don't affect other charts, even if they have the same data source. You can apply chart level filters by clicking on the chart and selecting the data tab, then creating a filter.
Example: You want to exclude "Google CPC" traffic from a specific chart. Apply a chart level filter for "source medium not equal to Google CPC".