Custom Data Responses
Each custom field is part of a group, that is itself attached to a "normal" civicrm entity (that can be a contact, an activity, a participant...), so the first thing you need to do is to find to what the custom group is attached.

the second thing it to be sure it's searchable. You can find both of them in the admin custom fields.

once you know where it is and that it's searchable, you can use the advance search, and you will have that field

As a side note: if your question provides a list of groups (all the sections or committees) it's probably going to be easier for you to ignore the custom field and directly show the list of groups