Template:TOC/styles.css

.custom-toc {
	/* used in the template */
	--toc-margin: .5rem;
}

/* hide all links under level 2 header */
.custom-toc.toclimit-2 .toclevel-1 ul,
/* hide all links under level 3 header */
.custom-toc.toclimit-3 .toclevel-2 ul,
/* hide all links under level 4 header */
.custom-toc.toclimit-4 .toclevel-3 ul,
/* hide all links under level 5 header */
.custom-toc.toclimit-5 .toclevel-4 ul {
    display: none;
}