bbp_admin_setting_callback_subtheme_id()

function bbp_admin_setting_callback_subtheme_id() {

	// Declare locale variable
	$theme_options   = '';
	$current_package = bbp_get_theme_package_id( 'default' );

	// Note: This should never be empty. /templates/ is the
	// canonical backup if no other packages exist. If there's an error here,
	// something else is wrong.
	//
	// @see bbPress::register_theme_packages()
	foreach ( (array) bbpress()->theme_compat->packages as $id => $theme ) {
		$theme_options .= '<option value="' . esc_attr( $id ) . '"' . selected( $theme->id, $current_package, false ) . '>' . sprintf( esc_html__( '%1$s - %2$s', 'buddyboss' ), esc_html( $theme->name ), esc_html( str_replace( WP_CONTENT_DIR, '', $theme->dir ) ) )  . '</option>';
	}

	if ( !empty( $theme_options ) ) : ?>

		<select name="_bbp_theme_package_id" id="_bbp_theme_package_id" <?php bbp_maybe_admin_setting_disabled( '_bbp_theme_package_id' ); ?>><?php echo $theme_options ?></select>
		<label for="_bbp_theme_package_id"><?php esc_html_e( 'will serve all Forums templates', 'buddyboss' ); ?></label>

	<?php else : ?>

		<p><?php esc_html_e( 'No template packages available.', 'buddyboss' ); ?></p>

	<?php endif;
}