Elements:Button Groups
            To create button groups simply wrap a series of buttons with the
            .btn class in a wrapper with the
            .btn-group class.
          
All button styles can be applied to the buttons within the group.
Styles
Default
Outline
Rounded
Button toolbar
Sizes
            By adding
            .btn-group-lg or
            .btn-group-sm to the
            .btn-group you can alter the size of all the
            .btn elements within the button group.
          
Large
Default
Small
Nesting
            You can also "nest"
            .btn-group elements within
            .btn-group groups if you want to use dropdown menus within the group.
          
Vertical Button Groups
            Button groups can also flow vertically by adding the
            btn-group-vertical class instead of the
            btn-group class.
          
 
                               
                              