Decrease the vertical spacing or leading between all 3 elements in the nectar slider- the large text, the sub text and the button

Add this into the Custom CSS box located in your Salient Options panel:

<p>#boxed .swiper-slide .content h2 {
    line-height: 30px;
}
.nectar-slider-wrap[data-full-width="false"] .swiper-slide .content h2 {
    line-height: 40px;
}
.swiper-slide .content p {
    padding-bottom: 0px;
}
</p>

Cheers