We don't have this per se.
Most "advanced" animations are a matter of taste, practice and good animation fundamentals.
If you need help with specific features, we can help point you in the right direction.
Beyond that, people sometimes show their techniques and steps in the Showcase forum: viewforum.php?f=5
There are some good ones there.
If you ask nicely, some artists/animators may share their process. Obviously, whether they do is entirely up to them.
And I've seen at least one group that sells third-party in-depth Spine tutorials.