Here's your guide on sharing documents with multiple Spaces.
1. After uploading your document, picture or video in a specific space, click on the three dots "..." button in the upper right hand corner for more options.
2. Select Share in other Spaces.
3. From the dropdown menu, select a different Space with whom you would like to share it.
Note: you will only be able to share it with another Space if you're an Owner of that Space. Here's an overview of the Roles & Permissions on the platform.
4. Select the destination folder for the shared document. You can also select the top "Files" section.
Note: If you want to share it within multiple other spaces you can select Share again in another Space before sharing.
There you go!
Note: you will always be able to see with which other Spaces a file has been shared by clicking on the arrow at the bottom right hand corner. Here's how to Remove the sharing of files in other Spaces.