я пробовал сделать так:
HBox pane = new HBox();
HBox hBoxTop = new HBox(5.0);
TextField textTop1 = new TextField();
TextField textTop2 = new TextField();
hBoxTop.getChildren().addAll(textTop1, textTop2);
HBox hBoxC = new HBox(5.0);
ComboBox<String> combo1 = new ComboBox<>();
ComboBox<String> combo2 = new ComboBox<>();
hBoxC.getChildren().addAll(new VBox(5.0, combo1, combo2));
Button button1 = new Button();
Button button2 = new Button();
Button button3 = new Button();
hBoxC.getChildren().addAll(new VBox(5.0, button1, button2, button3));
HBox hBoxBot = new HBox(5.0);
TextField textBot1 = new TextField();
TextField textBot2 = new TextField();
TextField textBot3 = new TextField();
hBoxBot.getChildren().addAll(textBot1, textBot2, textBot3);
pane.getChildren().addAll(hBoxTop, hBoxC, hBoxBot);
Scene scene = new Scene(pane, 600.0, 400.0);
но они у меня все наезжают друг на друга