Hello Andreas,

You can access deep structure like the you access flat structure fields but with some restrictions.

One of things to take care is use the compatible type for the component that is being accessed.

This link will help you ABAP Keyword Documentation

As per you screen shot below statement can be used to access first table.

Table type <tt> = output-getOrderResponse-<Structure1>-<table1>

You can also refer below blog series :

Deeper Dive into Deep structure - part 1

Deeper Dive into Deep structure - part 2

Deeper Dive into Deep structure - part 3

Deeper Dive into Deep structure - part 4