Click the plus icon:
Click the expand icon:
Scroll down to the Platform field and type in the value you want (LinkedIn). When you close the form window the new grouping items should display.
I don’t know the answer to your question but maybe you can try the following and see if it works:
Go to your workspace and duplicate the base you want to share and call it TempShareShare TempShare with your colleagueGet your colleague to duplicate Te...