Share Layer
From GapWiki
To share a layer select it and click Share. The following window will appear:
To share a layer with all GAP users, select Public and click Share. If the layer is already shared, you can unshare it by pressing Un-Share button
To share/un-share a layer with a specific user click Individual user and type the email address under which the user is registered on the GAP platform. Then click (Un)Share.
To share/un-share a layer with a certain community/group click Individual community and select the community from the drop down list. Then click (Un)Share.