.nav.nav-pills.justify-content-end{
    display: none !important;
}

There are different way you can do this operation .
you can use comma Operator(,) ,you can use no space between all all class .nav.nav-pills.justify-content-end like this and you can choose any of class and make display: none; like this

.justify-content-end{
    display: none;
}

Use coma operator(,) to add the same style to deferent classes

.nav,.nav-pills,.justify-content-end{
    display: none;
}

I want to put the class that have more than one class into my css, for examples I have this code in my html.

class="nav nav-pills justify-content-end"

And I want to change all of the above to disappear so I have to put “display: none”. I have tried this in css but it doesn’t seems to work.

.nav nav-pills justify-content-end{
    display: none;
}

Ps: I use bootstrap framework