Hi Pavel
No, clicking on the top of columns does not sort the column below it. But if you click and drag you can change the order and/or column width of columns. If you right click you can add new columns.
Have you discovered the following (in the left hand column) Filter ==> Group & Sort ==> Group by
and/or ==> Sort
Note that if you are attempting to change the View being used by a Tab (AKA Workarea) that is Locked, MLO will create (and instantly take you to) a new Tab. This can be very confusing. To avoid confusion I recommend that you carefully Save your new views.
If you want to change a View that has been locked by a Tab, one solution is to start changing the view and top allow MLO to take you to the new Tab. But if you save the View that is being used by the Tab, you can overwrite the old version of the view with the new version of the view. This means that the original tab will now be using your modifications to that View. And you can in fact now delete the new Tab that MLO created.
J