Problem summary
You cannot use nested filter logic in a Google Analytics 4 data source. The filter builder lets you join all conditions with either OR or AND, but you cannot combine the operators in one filter.
Error message or symptoms
The dimension filter provides one grouping option for all conditions: either OR or AND. You cannot group conditions or combine both operators. For example, you cannot create the filter A OR B OR (C AND D).
When does this occur
You configure a Dimension filter on a Google Analytics 4 data source.
You need to combine OR and AND conditions.
A flat filter returns more rows than you need.
Root cause
The Google Analytics 4 connector supports only flat filter groups. The operator that you select applies to every condition in the group.
Solution
You cannot create nested filter groups in one Funnel data source. Use a flat filter if you can express the required logic with one operator.
Workaround
As a workaround, split the logic across separate data sources:
Divide the filter into branches. Each branch must use only OR or only AND.
Make sure that each row can match only one branch.
Create one Google Analytics 4 data source for each branch.
Combine the results in your report or export.
This workaround can produce duplicate values if the filter branches overlap.