Change media gallery title with BuddyPress username

functions.php

/**
 * Change title of "Media Gallery" in "media" tab.
 * This functions needs "Buddypress" plugin to be activated.
 *
 * @param  string $title Title of Media gallery.
 * @return String        Updated title.
 */
function rtm_gallery_title( $title ) {
    // Get user name for current profile.
    if ( ! function_exists( 'bp_get_displayed_user_mentionname' ) ) {
        return;
    }
    $title = '@' . bp_get_displayed_user_mentionname() . '\'s Media';
    return $title;
}
add_filter( 'rtmedia_gallery_title', 'rtm_gallery_title' );