A part the existing features that build the query automatically there is also the possibility to further implement the query by hand coding in the last text field after the Add (concatenation operators) menu but to do this it is needed to enable this section by selecting a column in the Alt. Where menu, this means we must have there a condition with a value otherwise this condition and the following implementation will not be added to the query, just to avoid errors.
Let's have a look again at the first example, we have there the first level implemented with an "Order By POS" but preceded by the condition "SUBID = 0". If you try to empty the Value field you will see that in the Levels list this part of the query is removed, that means we must have there a condition before continue to implement.
Well suppose we are in a different situation with a different table and we want implement some way the query by hand coding but we don't want the influence of the preceding condition. In effect this behavior will not let you do it if you don't put there a condition, therefore the workaround is to put there a condition that do not any filtering returning all the records.
Using the second example to demonstrate it we remove the Price filtering from the first level and we put there an uninfluent condition then we Order By the count of each product category. This will return the entire list of products but ordered in a way that the product category which has the lower number of records will appear at the top and the product category with the highest number of records will appear at the bottom.
The image doesn't show the complete implementation which is "GROUP BY Product ORDER BY count(Product) ASC". Note that Group By must always come before the Order By therefore you must not assign it in this case with the checkbox because this it will put it in the wrong position.