I set an attribute for an element and then applied a filter that excluded the element based on the attribute. However, the element is still visible:
If you make changes in the content or the filter expression, you will need to apply the filter to the topic. For example, if you apply a filter to the topic and then tag an element with an attribute that is included in the filter, the filter is not immediately applied to the updated content. You need to apply the filter to the topic.
I applied a filter to a topic and the structure of the topic is now broken:
You need to take care not to break the structure of the topic. If the filter that you apply to a topic causes a mandatory element to be hidden, the topic structure is broken. FrameMaker does not prevent you from doing this; however, the Structure View will indicate the break in the topic.
Broken structure caused because the dt tag is hidden by the applied filter
What happens if I apply different attributes to child and parent elements in a topic?
If a filter causes a parent element to be hidden then the child elements are hidden, irrespective of the attributes applied to the child elements. However, if a filter causes a parent to be shown and a child to be hidden, the child is hidden.