Properties of Characteristic Restrictions and Default Values 
In the Properties of Characteristic Restrictions and Default Values dialog box, you can decide how to sort the characteristic restrictions.
Features
Tab Page: General
Sorted Display
Characteristics are sorted either alphabetically or by the system, by default. It is not possible to change the way the characteristics are sorted. In BEx Web Applications you can now define your own sorting instead of using the internal system sorting. This affects the display in the information pane (Information Field Web item), in the navigation pane and in the filter pane, provided that alphabetical sorting is deactivated.
More information:
Activities
Select the checkbox and sort the characteristic restrictions as required.