Build a time view query in Explore that will count unique user actors that is filtered to all user actors and is starting at 1 month ago and ending now. Use the time view options below starting and ending time and set it to every 1 week (trailing will automatically update to 1 week). Use time view to visualize the result.
Once your query returns pay attention to the dots on the line. When using time options on a time visualization you have full flexibility to choose the time range that each dot represents. Note in this situation that each dot will now represent a 1 week period.
Note: The numbers do not need to be an exact match as the data changes over time. The query construction is what is most important. See images below.
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