There are many file formats which use specific record types to mark the beginning and end of multiple-level structures within a file. A file containing a library of object code modules (produced by compiler or assembler) might be structured something like this:
I’m not familiar with many of the templates that come with 010 Editor.
Are you looking for an example of how to identify different record types for different types of structs? If so then the ZIP.bt template does this:
It uses the ReadUInt function to pre-read data before creating the structs.
Sorry. I didn’t mean to submit this incompletely written topic at all. It needs some more thought before I can express it cogently.