The member selector slicer is a space-efficient control. 

The slicer provides full access to the member selector and search functionality. From the Anaplan XL menu, select Slicer > Analysis Services...

Insert a hierarchy slicer, choose your hierarchy, and select the slicer type as highlighted below: 

The Insert Hierarchy Slicer with the setup and geography displayed.

Select OK to return to your workbook. Below is a slicer example:

Select the ellipsis and the Member Selector displays. The selector enables you to run some of the Advanced Member functionality, such as search.