You can define how multiple selected filters are combined on a Quick Controller using the following options:
“AND”: only show issues matching all the selected filters.
Example: display issues that are “bugs” and are “in progress”.
“OR”: only show issues matching any of the selected filters.
Example: display issues that are either “bugs” or have a “high priority”.
“Do not combine filters”: only one filter is active at a time. Every time a filter is selected, the previously selected filter (if any) is disabled.