How do I filter or sort the board?

You can filter the board by a Group by viewing the board by that Group from the menu.  Instead of selecting 'Everyone' just select the Group you would like to view.

You can sort the board from the 'Sorting' settings on the menu.

You can sort the board by:

Name = Alphabetically by name

Status = In users followed by out users

Time = The most recent status updates will appear first

You also have the option for ascending and descending, so if you wanted to sort it reverse-alphabetically by name (Z-A) you can do that.