Develop a form for directories on Android

A handbook form should be developed for further use in several projects. The structure of the directory is as follows: a side menu with items (an example in the attachment), by clicking on which subitems are opened, and by clicking on them - the contents of the help item (an example in the archive). The directory files are local. The item can immediately open the content without sub-paragraphs, and sub-paragraphs can contain additional sub-paragraphs (sub-paragraphs in file 3 in the archive), i.e., the sub-paragraphs can contain additional sub-paragraphs. There should be hierarchical content like .chm files (in principle, data can be taken from it). The content of the reference will consist of text, tables, figures. There should be support for links from one section of the help to a certain text in another section (hyperlinks). Also search the entire text of the directory and save the last viewing place. Settings - size, font color, background color.
The files have .apk Testo nascosto of the project, but it has a side menu without sub-items, links and search do not work, no settings.