How to access sub menu in tool bar using Magic Mouse 2?

How do I access sub menu in tool bar using Magic Mouse 2? There is a drop down arrow but have tried right clicking (clicking far right side of the Magic Mouse 2 with the option enabled in settings) tried left clicking etc… but nothing happens how do I access this sub menu exactly?

You mean the context menu? You can check the settings of the Magic Mouse in System Preferences and enable the right clicking on the right side, or use two finger tab (or whatever thy suggest there).

Or use can use the way as it was before two buttin mice: Hold the Ctrl key when you click.

I don’t think it’s a right click for what I was trying to achieve, I think I hold down left click on the tiny arrow?

Click and hold anywhere of the tool icon. Or add the Shift key to the tool shortcut. So pressing E picks the Eraser, but pressing Shift-E toggles between the Eraser and the Knife.