"toolbars": {
    "mainMenuIcon": "./plugins/img/3dFinditEyeColor.svg",
    "mainMenu": [
      ["customButton1_Group1", "customButton2_Group1", "customButton3_Group1"],
      ["customButton1_Group2", "customButton2_Group2", "customButton3_Group2"]
    ],

Sub-arrays create groups. However, this only works for the "mainMenu" toolbar, as the others normally only display individual buttons.

Group separation line

Buttons in main bar

In the following example, the buttons are assigned to two different groups:

      "customButton1_Group1": {
        "type": "VBS",
        "icon": "./plugins/img/3dFinditEyeColor.svg",
        "name": {
          "de-DE": "custom button 1 de",
          "en-GB": "custom button 1 en"
        },
        "script": "/plugins/vbb/custom1_startup.vbs",
        "tooltip": {
          "de-DE": "custom button 1 de",
          "en-GB": "custom button 1 en"
        }
      },
...
...
      "customButton1_Group2": {
        "type": "VBS",
        "icon": "./plugins/img/3dFinditEyeColor.svg",
        "name": {
          "de-DE": "custom button 1 de",
          "en-GB": "custom button 1 en"
        },
        "script": "/plugins/vbb/custom1_startup.vbs",
        "tooltip": {
          "de-DE": "custom button 1 de",
          "en-GB": "custom button 1 en"
        }
      },

...