You could use .addAction() method:
Notification notification = new Notification.Builder(context)
    // Show controls on lock screen even when user hides sensitive content.
    .setVisibility(Notification.VISIBILITY_PUBLIC)
    .setSmallIcon(R.drawable.ic_stat_player)
    // Add media control buttons that invoke intents in your media service
    .addAction(R.drawable.ic_prev, "Previous", prevPendingIntent) // #like this
    .addAction(R.drawable.ic_pause, "Pause", pausePendingIntent)  // #this
    .addAction(R.drawable.ic_next, "Next", nextPendingIntent)     // #and this
    // Apply the media style template
    .setStyle(new Notification.MediaStyle()
    .setShowActionsInCompactView(1 /* #1: pause button */)
    .setMediaSession(mMediaSession.getSessionToken())
    .setContentTitle("Wonderful music")
    .setContentText("My Awesome Band")
    .setLargeIcon(albumArtBitmap)
    .build();
Source : http://developer.android.com/guide/topics/ui/notifiers/notifications.html#controllingMedia