Allow to make connection to specific SharePoint site or subsite and not to entire SharePoint domain due to security concern

We are trying to create form with workflow able to save attachments in SharePoint site for other processes usage. However, the workflow connector doesn't allow to make connection to specific SharePoint site. With only connection to entire SharePoint domain, this raised a concern by our security admin of which it is a risk. It is important as large organization having a lot of sites in SharePoint with specific task usage and cross site's function.