Group members in the member selector let you aggregate members that don't belong to a parent. This gives you a total for these members.
Members can be grouped in the Member Selector by right-clicking on the member list or based on slicer choices or an Excel range. For example, below is a slicer with France, Germany, and the United Kingdom selected:
To display this selection as one row on the grid, go into the Hierarchy Editor and select More and then Group Members from the dropdown:
The grid now displays one row for the three slicer choices. Give the slicer a title and it'll display that instead of the XL3WithMember.
Review Grid Calculations.
