Recently running into a problem with trying to define structure references that exist at different areas in the binary based on the info fields of previously seen structures. In particular, I'm trying to take an offset field i've defined in a 'Header' struct, and place another defined struct at that offset. For some reason I can't seem to find a way to do this, I've been messing around the layout of the grammar and couldn't find any documentation related to how to access special APIs for the fields of other structes (there was an example using "prev.size" in the tutorial).
Linked is a picture that hopefully explains better. Ideally I would want the "Image" struct to start at the file offset in 'image_offset' provided by the header, up to the length provided by 'image_size'. However currently they just occupy the space side by side, ignoring the offset field.
What would best practices be in this case?