Uhm I'm not sure if there is a good way to deal with this, What I have done before Is painted everything and added a mouselistener to see where a user clicked to enabled/disable setitngs.
But if you are going to want a dropdown it's not going to be easy to do it in the paint itself.
Maybe you can try to get the position of osbots Jframe and move the Jdialog based on that.
You could get the OSBot Frame by doing this I guess:
for (Frame frame : Frame.getFrames()) {
if (frame.isVisible() && frame.getTitle().startsWith("OSBot")) {
//Access to Frame X and Y
}
}