Bootstrap 4 выпадающие меню Navbar.
Bootstrap 5 (update 2021)
Use the dropdown-menu-end class on the dropdown-menu to align the items inside the menu right..
<div class="dropdown-menu dropdown-menu-end">
<a class="dropdown-item" href="#">Link</a>
<a class="dropdown-item" href="#">Link</a>
<a class="dropdown-item" href="#">Link</a>
</div>
https://codeply.com/p/kWLLKdjdpC
Bootstrap 4 (original answer)
Use the dropdown-menu-right class to align the items inside the menu right..
<div class="dropdown-menu dropdown-menu-right text-right">
<a class="dropdown-item" href="#">Link</a>
<a class="dropdown-item" href="#">Link</a>
<a class="dropdown-item" href="#">Link</a>
</div>
http://codeply.com/go/6Mf9aK0P8G
Tiago F2