Pretty basic, the menu allows for a separator, which is a line.

It would be nice for the button group to allow for a separator that is just white space/extra padding between specific buttons, similar to how the buttons are rendered on this editor.

Using multiple button groups will not resolve the issue, when only one button at a time from is allowed to be clicked.

For example, the below is my button group:

Add  Include Exclude Insert Move Undo

I would like to have more space between specific pairs of buttons

The above buttons will perform specific operations on a set of data.  They are mutually exclusive, in that only one operation can be executed at a time.  It would be nice to have some more space between specific pairs of buttons.  For example:

Add  Include Exclude   Insert Move  Undo