To visualize the shares you must access the Competition module, section Monitor your Competitors and go to Sellers or Official Stores Watchlist.
2) In the comparison chart at the bottom of the view, you will find the revenue share and the share in units for each group.
The shares represent the distribution of the total amounts in units or turnover among the selected sellers. If you do not select any competitors and all of them appear in light gray, then the sales will be distributed among all the members of the group.
For this analysis, we recommend filtering down to the leaf subcategory, so that the share is correctly distributed among sellers, official stores, and listings.