Outlier groupings allow you to display a subset of the selected members grouped together into a common set, often called "Others".
You can select the criteria to define what is grouped and give the group a name. From Version 8, you can also select a member to always display, whether or not it would usually be included in the list.
The simplest example is using a Ranking. Normally we return the top 10 members, but we may also want a summary of the items not displayed.
We start with a long list of products:
If we add a normal ranking we get the top 10, but lose the other products which may be significant:
Instead we will remove the ranking and add a Outlier Grouping.
In this dialog we will just use the default top 10 ranking, although we could also group by value (Filter), or chose certain members that will go into the group.
Note also the option to 'Always show member'. This forces a specified member to always be shown. For example Top 10, plus a specified member (if it is not already included in the top 10), plus 'others'. In this case always show member was not specified, and the selection results in the following grid.
Note that we choose "Keep these members separate". We could change this and select "Group these members" to have the top 10 grouped, and all other members shown as normal.
User driven grouping
In this example we will have members picked, and allow the user to select which go into the "Others" group by selecting some of them in a slicer.
We start with a simple grid listing the Sales Territories. We would like the user to be able to select some of the territories, and have those go into the "Others" group. The remainder will be displayed as normal.
This is the initial setup with the slicer not linked to anything.
We open the member selector for Sales Territory and add the Outlier Grouping.
The settings here are to group "Specific members", and to "Group these members".
All that is left to do is define the members in the grouping, so we simply pick the slicer we already have.
The end result is a slicer allowing the user to dynamically group the results.
You could of course reverse which members are grouped/separated to get the opposite effect.