An org I'm working in has an existing custom LWC component that functions as a dynamic look up. You can define which object it looks up to but in this instance it is working with Accounts. When clicking on one of those outputted records, that record is added to the 'filterAccounts' attribute on the parent component. The 'filterAccounts' attribute is bound to a lightning:pillbox's items attribute and the pillbox displays the record in the pillbox.
Where could it be? How can I track down where this attribute is defined so I can create the same on my new implementation of this component?