Listing ordered components, recursively
If I understood correctly, you have to traverse a list of components where each element has a hierarchy-like structure?

Try the visitor pattern https://www.tutorialspoint.com/design_pattern/visitor_pattern.htm it is a very clean solution of what you're trying to do without any static methods.

And for traversing the children of each component, I think you're trying to do a pseudo-BFS, but it's a bit confusing. BFS is very tricky using recursion. The iterative version kf BFS should be something similar to this https://stackoverflow.com/questions/16380026/implementing-bfs-in-java