When a selection includes elements of different categories, you can use a filter to remove unwanted categories from the selection.
To select elements using a filter
To select only elements that are completely within the boundary of the box, drag the cursor from left to right. To select any elements that are wholly or partially within the boundary of the box, drag the cursor from right to left.
The Filter dialog lists all categories of the elements that are currently selected. The Count column indicates the number of selected elements in each category. The total number of elements currently selected displays at the bottom of the dialog.
As you modify selections, the totals update in the dialog and on the status bar.