The digest, located in the side panel too (see the Section called The side panel in Chapter 2) is very handy when working with huge documents.
Just click on the digest tab to access it.
Click on the parse document title to get the document folded by declaration.
Double-click on the desired line in the digest panel to get access to it in the document.
You will see the document scrolling up/down to the first line of the declaration, which will be marked with a chevron in the margin.