Figured I’d add something to help people out who want to add a row to a flexible content field that’s inside of another flexible content field.
acf.addAction( 'append', function( $el ) {
if ( $( $el ).hasClass( 'layout' ) && $( $el ).is( '[data-layout="level1_layout_name_here"]' ) ) {
var nestedFlexField = acf.getField( $( '.acf-field[data-name="NESTED_FLEX_FIELD_NAME"]', $el ) );
nestedFlexField.add( {
layout: 'level2_layout_name_here'
} );
}
} );