Greenberg studied the variation of Iwasawa invariants across \(\mathbb {Z}_p\) -extensions of a number field F. One of his key ideas was to appropriately topologize the set of all \(\mathbb {Z}_p\) -extensions of F. Sören Kleine refined Greenberg’s topology to investigate the variation of Iwasawa invariants for Selmer groups of abelian varieties over \(\mathbb {Z}_p\) -extensions of number fields, providing bounds on their \(\mu \) -and \(\lambda \) -invariants. In this article, we adapt Kleine’s techniques to the context of function fields. Specifically, we generalize the application of topology to analyze the variation of Iwasawa invariants associated with Selmer groups over \(\mathbb {Z}_p\) - and \(\mathbb {Z}_\ell \) -extensions of function fields.