To get the active filters count, you should use {active_filters_count:QUERY_ID}
However, it wouldn’t display the number of selected options like your expected result. It’s returning how many filter elements’ logic is used for the current target query.
Sorry. Of course, I meant active_filters_count and not query_results_count_filter.
But isn’t it confusing how active_filters_count works at the moment? I checked a few shops and everywhere it is the case that it is not the filter elements that are counted, but the filters that are actually selected (checkboxes, select, dropdown, etc.).
I have discussed with the team, and we agreed that this dynamic tag should return the total active filter values instead of the number of filter elements.