RE: Dynamics 365 attachments with Flow
Hi,
First of all, you need to create MS Flow for each and every entity for which you want to move the attachments.
Now, since you know that you have a hierarchical folder structure (i.e., based off of Account) in SharePoint, then based on the customer (Only if it is an Account) that is selected on Incident, you can create a folder within the selected customer folder on SharePoint or else you can just dump the attachments in the default Document Library for Incident.
Though bit complex, this is the way to achieve your requirement through MS Flow, or else you can check out our product Attach2Dynamics that would do the needful.
Hope this helps.
Thanks!