<div class="btn-group-vertical mb-2" role="group">
<button type="button" class="btn btn-outline-secondary">Button</button>
<button type="button" class="btn btn-outline-secondary">Button</button>
<div class="btn-group" role="group" ngbDropdown>
<button id="btnGroupDrop6" type="button" class="btn btn-outline-secondary" ngbDropdownToggle>
<div ngbDropdownMenu aria-labelledby="btnGroupDrop6">
<a class="dropdown-item" href="javascript:void(0)">Dropdown link</a>
<a class="dropdown-item" href="javascript:void(0)">Dropdown link</a>
<button type="button" class="btn btn-outline-secondary">Button</button>
<button type="button" class="btn btn-outline-secondary">Button</button>
<div class="btn-group" role="group" ngbDropdown>
<button id="btnGroupDrop7" type="button" class="btn btn-outline-secondary" ngbDropdownToggle>
<div ngbDropdownMenu aria-labelledby="btnGroupDrop7">
<a class="dropdown-item" href="javascript:void(0)">Dropdown link</a>
<a class="dropdown-item" href="javascript:void(0)">Dropdown link</a>
<div class="btn-group" role="group" ngbDropdown>
<button id="btnGroupDrop8" type="button" class="btn btn-outline-secondary" ngbDropdownToggle>
<div ngbDropdownMenu aria-labelledby="btnGroupDrop8">
<a class="dropdown-item" href="javascript:void(0)">Dropdown link</a>
<a class="dropdown-item" href="javascript:void(0)">Dropdown link</a>