Select the Query menu option under the View menu or press [OPT]+[F7].
Open the Query window. Then select the how to apply the search criteria from the drop down list(the default value is CONTAINS). Next, enter the search criteria. Additionally you can tell the search which bfs drives to search by using the volume drop down list. Finally, select query. BeCommander will perform the query then populate the selected pane in BeCommander. To exit the query results in the BeCommander pane simply press [BACKSPACE].
Choose any search criteria to constrain which files to search in(note: currently BeCommander requires this. This is a bug that will be addressed.) Next check off Find Text. Then enter the text to search for and press Query. Like Searching for files the currently selected pane in BeCommander will be populated with the results of the query.