A semantic map created from a document is a kind of analog to the google map. It maps and names everything that may be of interest to the user (so-called points of interest). Within the map, the user searches for what is important to them. A semantic map is more detailed than a tree of knowledge. It is a complementary format to the .pdf format of the document.
As an example, let's take a semantic map of the law. It lists all the rights and obligations of the individual entities to which the law applies. Currenty, looking at the legislation at EU portal EUR-lex, the user cannot find out, which paragraphs apply to them.
Example of semantic map: