What does "parent" mean in filter block


in the filter block, i do not get “parent” mean here.

i have categories (in woo products categories) like:

parent: AAA
child: 1111
child: 2222
child: 333
child: 444
child: 555

i want filter the child category item out

i should choose the parent option as : AAA, right? ( when i did like this, nothing happening)

thanks for the help in advance.