In the comics, Jonathan Hickman has gone to great lengths to broaden the scope and depth of Hydra to where they are practically everywhere. One facet of the organization deals with scientific research, while another studies interdimensional spells, and yet another is infiltrating the upper levels of government. The group is so large and multifocused that the TV show could use them as the big bad for the entire series run by just facing off against one "arm" of the Hydra each season.
It goes back a bit further than Jonathan Hickman, to Dan G. Chichester's runs - with or without collaborating writers - on Nick Fury
, and so on. The occult ops arm was called the Department of Occult Artifacts(DOA).
Hickman's added a couple of new things to help cover Hydra's financing and research in various fields: