Create a Selection Module with User dimension and line items as per SS,
In planning module, create a filter line item and change the applies to and put the formula as per below pic,
Then apply the filter based on above created line item,
Publish only the selection line items to the dashboard and do your selection, now the grid will get updated based on your selection.
I hope this elaborates you!! Let me know if you have any doubts.
Note: You can make use of the dependent drop down, lets say if there is any relation between country and retailer then based on Country selection, My retailer selection will show only respective items. Ex below,