Filter Selection is the tool using which you can apply condition of properties to Add or Remove entities in selection
In this dialog box some properties are given like layer, entity type and some other conditional properties.
Layer : Using this property you can select the entity with desired layers. Just mark in cell of 'Select' column check box of desired layers.
Entity Type : Using this property you can select desired entities. Just like you want to add polyline in to selection then mark in checkbox of 'Select' column infront it.
Conditional Selection of Entites : Some time we need to select some entities on the basis of there properties like length inclined angle and etc. So to use properties click on property cell, a list will appear. Select desired property, in next condition cell select any one condition operator (like =, <, >) add comparing value in value cell. Also you can add logical AND and OR operator to add more compare with more properties.
Add To current Selection : After applying condition, using this button you can add the entities in selection.
Remove From current Selection : After applying condition, using this button you can remove the entities from selection.