The Search and Filter buttons sit beside the book name on a song list. Both select from the current book, and they can be active at the same time. An active button stays highlighted.
Tap Search. A Search songs field opens under the book name. Type, and the list shrinks as you type. The clear button closes the field and empties the text. If nothing matches, the list says No songs match the search.
The Fields list controls which fields to search, and how to match:
Tap Filter to open Song Filter.
The song list shows the songs that match the filter.
Choose how the criteria combine: AND - all must match or OR - at least one must match.
The left pane is Available Fields. Tap to add to filter.
The right pane is Filter Values. Choose comparison type and value.
The delete icon on a line removes that line.