please look here for sfx related things in brawlbox
the place you are looking in your screenshots are only for SEQ to brstm rerouting hacks, not actual sound injections or playback
double click on an item in the long circled list to see th e sounds contained within, and you can playback the sounds given that the one you are checking is either a BNK or SWD
please note that this table will disappear if you click on any other items in that folder structure
the root "file" (selected by default on opening the file with brawlbox) must be selected at all times for that table to appear
it's hard to miss unless you click on other things beforehand