One way to arrange items of information so that they are more easily understood is to filter out those which aren't important at that moment.
Each viewer has its own filter. It is a pane at the far right of the viewer with the word "Filter" at the top.
You can expand or contract the filter pane by grabbing the bar which separates it from the actual whiteboard and dragging it (with the left mouse-key pressed) to the left or right. The small arrows towards the top of this separator expand or shrink the filter with one click.
Please note that we combined priority "1" OR "empty" further up, but in this last step we set the filter to show us the items with "Priority=1" AND "Status=Finished".
This means that within an aspect the filter combines using "OR" and between aspects it uses "AND". That makes sense because one item can't have two priorities - it has either one OR the other.
If you activate all the values (using Ctrl) for an aspect, it has the same effect as if you activate none of them.
To deactivate the filter (i.e. you want to see all the items) simply click on a branch (the name of an aspect).
To remove an aspect from a filter (for instance if the priority becomes irrelevant), simply close the priority branch (by clicking on the symbol directly to the left of its folder symbol). This means that selected leaves cannot hide in a closed branch - so you don't have to open a branch to see whether any values have been selected there.
If you need a filter which uses "OR" between aspects, open a second view and have one part of the filter in one view, and the other in the second view.
Filters used in combination with colors in a column view form a powerful way to simplify your way of seeing your information.