Hi,

If you want block shortcode show list post of category, please go  to edit  this shortcode , click "Builder query" button and choose category you want as screenshot http://prntscr.com/m20tyl

If you want use ajax filter, please edit block shortcode you want add filter, then go to "Ajax Filter" tab then choose filter by category or tag as screenshot http://prntscr.com/m189mn

Best Regards,

PenciDesign