Horizontal

<div class="btn-group" role="group" aria-label="Basic example">
    <button type="button" class="btn btn-dark">Left</button>
    <button type="button" class="btn btn-dark">Middle</button>
    <button type="button" class="btn btn-dark">Right</button>
</div>

Input Group

<div class="btn-toolbar justify-content-between mr-2" role="toolbar" aria-label="Toolbar with button groups">
    <div class="btn-group mb-2" role="group" aria-label="First group">
        <button type="button" class="btn btn-dark">1</button>
        <button type="button" class="btn btn-dark">2</button>
        <button type="button" class="btn btn-dark">3</button>
        <button type="button" class="btn btn-dark">4</button>
    </div>
    <div class="input-group mb-2">
        <div class="input-group-prepend">
            <div class="input-group-text" id="btnGroupAddon2">@</div>
        </div>
        <input type="text" class="form-control" placeholder="Input group example" aria-label="Input group example" aria-describedby="btnGroupAddon2">
    </div>
</div>

Vertical

<div class="btn-group-vertical" role="group" aria-label="Vertical button group">
    <button type="button" class="btn btn-dark">Button</button>
    <div class="btn-group" role="group">
      <button id="btnGroupVerticalDrop1" type="button" class="btn btn-dark dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        Dropdown <svg> ... </svg>
      </button>
      <div class="dropdown-menu" aria-labelledby="btnGroupVerticalDrop1">
        <a class="dropdown-item" href="#">Dropdown link</a>
        <a class="dropdown-item" href="#">Dropdown link</a>
      </div>
    </div>
    <button type="button" class="btn btn-dark">Button</button>
    <button type="button" class="btn btn-dark">Button</button>
    <div class="btn-group" role="group">
      <button id="btnGroupVerticalDrop2" type="button" class="btn btn-dark dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        Dropdown <svg> ... </svg>
      </button>
      <div class="dropdown-menu" aria-labelledby="btnGroupVerticalDrop2">
        <a class="dropdown-item" href="#">Dropdown link</a>
        <a class="dropdown-item" href="#">Dropdown link</a>
      </div>
    </div>
</div>