To manage shares, you need to have been provided with rights to manage shares. Your shares are listed in the Shares section of your business account. Go there and explore the two available tabs. Those are: My Shares and Shared with Me.
In the My Shares tab you get a list of all shares you have made to other users, in or outside the company.
The Shared with Me tab lists all the shares you have received from other users, either from the company, or not.