The ScienceMesh app gives a GUI where the user can generate and paste OCM invitations. You can get to it by clicking the ScienceMesh icon at the top bar of the Nextcloud GUI.
The app GUI only shows the sending and receiving of ScienceMesh invites. The actual sharing of a document or folder, and the receiving of a shared document or folder, works the same way as for sending and receiving other share types in Nextcloud.
When searching for a collaborator to share with, remote ScienceMesh users who accepted your invitation will show up.
If you have any questions about how to share a folder or document across ScienceMesh through Nextcloud,
or you received a ScienceMesh invite from a remote colleague and don’t see how to accept the invite and
receive the share, please ask @michielbdejong
in Gitter chat for help.