If you add multiple filters, they can be united in groups. A group consists of several filters and/or subgroups, united with a logical operator (AND or OR). The group header in the Filters pane indicates which logical operator is used in the group. All means that rows must satisfy all group filter conditions and subgroups (AND operator is used). Any means that rows must satisfy at least one filter condition or subgroup (OR operator is used).
Initially, one root filter group is created which requires rows to satisfy all its filters and subgroups.
To add a subroup to a group, click the group header and then click +Add subgroup in the Details pane.
To change the group operator, click the group header and then click All or Any depending on the operator you want to apply.
To remove a group, click its header in the Filters pane and then press the Delete key or click the button in the Details pane header on the right side of the page.
You can also temporary disable a filter group in a query without removing it. For this click the button in the Details pane header. This will remove the filter group from the generated SQL statement, but keep it in the Query Builder so that you will be able to re-enable it. To enable it back, select it on the Result Fields pane and click the same button in the Details pane header again.
Note that you can copy a filter from one group to another by dragging it to the target group.