To collapse elements manually, do the following:
Figure 1. The section element to be collapsed.
Figure 2. The section element collapsed.
If there is a Folding List for your document, collapsing will collapse not the current element but the closest parent element that is mentioned on the list. Suppose you frequently collapse chapters and sections, but never paras. If you want to quickly collapse the current section without moving the cursor from the current para, you can narrow the list of collapsible elements. For details, see the folding-list element in ../developers_guide/document-template-properties.html#doc-template-properties__folding-and-large-document-support.
Figure 3. Selected elements collapsed.