How to make a sidebar nav collapse to a drop-down nav small widths in Bootstrap

[Notorious.]

In Bootstrap, is there a way to make a sidebar nav (class="nav-list") collapse to a drop-down nav at low widths? To illustrate:Move from this:

To this at a given width breakpoint:

I want the sidebar to be the main nav at desktop widths, but don't want the full thing displayed on mobile.