Within allThings you have a global setting that lets you switch on/off the categorized view of all collections.
When you switch it ON, you do not get a plain list of all records when you enter a collection. Instead you get the top categorisation. All values of the top category field are listed and there is a counter how many records belong to each value of this field.
When you enter one category, that means your choose one value of this categorization field, your get to the second categorisation level. That means all records in the chosen category will be displayed categorized again. You can use as many categorisation levels as you want.
Defining a categorisation field is possible in collection definition screen. You can add new data fields or remove them. Your even can change their order.
Each data field of type "choice field" can be set to be a categorization field. Just switch "use for categorization" to ON. If you have all your categorization fields defined, go on to define the levels. Top categorisation will be the upper most "choice field used for categoristaion" in the data field list of your collection type. Second categorisation level the second "choice field used for categoristaion" in the list from top to down and so on. If you want to change categorization levels, just change data field order.