Wrap a series of buttons with .btn in .btn-group.
Combine button-like checkbox and radio toggle buttons into a seamless looking button group.
Combine sets of button groups into button toolbars for more complex components. Use utility classes as needed to space out groups, buttons, and more.
Feel free to mix input groups with button groups in your toolbars. Similar to the example above, you’ll likely need some utilities though to space things properly.
Instead of applying button sizing classes to every button in a group, just add .btn-group-* to each .btn-group, including each one when nesting multiple groups.
Nesting
Make a set of buttons appear vertically stacked rather than horizontally. Split button dropdowns are not supported here.