Button Dropdown

Any single .btn can be turned into a dropdown toggle with some markup changes. more details.

For Square Buttons With Dropdown add class .btn-square .

For Square Buttons With Dropdown add class .btn-outline-*.

For Outline Square Buttons With Dropdown add class .btn-square btn-outline-*.

Similarly, create split button dropdowns. Read bootstrap documentaion for More Details

For Split Square Buttons Dropdown add class .btn-square .btn-primary-* .