Currently when you are viewing a company, search is limited to within that company, with a toggle option to search across all companies.
It would be helpful to have another toggle option to expand the search scope to the company being viewed, plus sub-companies, sister-companies, and parent companies (essentially, expand the scope to all associated companies).
It may be useful to have an option for this company+related companies search scope to be the default selection, with toggle options to exclude sub/sister/parent-companies, or expand the search scope further to all companies.
ETA: It would also be very helpful if the Related Items search had these additional scopes as well. Meaning, when you click New on Related Items, and are searching for the item to relate. The ability to expand the scope to all related companies (sub, sister, parent) without expanding the scope to all companies would be dope.