Get better insights across multiple data sets.
Create a new document and write a hypothesis of what you want to discover through data comparison in Google Data Studio.
Make sure the data sources have at least one field in common to use as a join key. You can find sample data online.
In the Data Source panel, select the data sets - including your new data set - that you want to blend.
Click on Join Keys in the first row of the data set and search for a unique key that is similar across both data sets.
For example, Website URL or User ID.
Name your new blended data set and click on Save.
Access the chart properties on the right side of the panel and use the search option to find your new blended data set.