Create a List & Search based on categories, I will describe it as parent.
Create menu item for this parent list and search
In menu item assign live value for desired category’s id
Create a child category list and search
in your parent list view have a list field and reference your child search and pass the id to the child search
parent_id=id
There are ways to refine this but that is the starting point.
Abd as always, with searches you got to have debug on and you must get your head round match/3