All queries offer the ability to search for fields to use in filters and output.  This search functionality is opened by going to Edit > Find in the query, and then typing the search term in the Find field that appears at the bottom of the Field Explorer.  However, in some instances when searching for a field using this functionality, users may receive the error:

Query node for view alias 'Arkansas Public Ed' with a parent of 'V_QUERY_CONSTITUENT' was not found. One or more source views may have been altered since this ad-hoc query was created.