You can attach items from My Resources in your Home site to any location in another site where you have permission to add attachments. For example, you may attach a file stored in My Resources to an assignment or forum post in one of your course sites.
In the site where you want to add an attachment, go to the tool where you want to add it, for example, Assignments.
Click on the item where you want to attach the file, for example, the title of an assignment.
Click the button or select files from 'Home' or site.
Under Select a resource, Home, click the folder with a solid folder icon (Open this folder) that contains the file you want to attach.
The name of your selected file will display under Items to attach. Depending on how the assignment is configured, you can attach an additional file by choosing Attach a copy beside another file.
When you have selected the files you want to attach, click Continue.