On Engage there are a few places where fields begin populating as the user is typing. First, a character field (such as the keyword or any user-entered text field) will often remember previously typed text strings; this is common on web pages.
Another place where values begin to filter out as the user is typing is in a choice field. As a user is entering data for a new requisition, study, or shipment, they can type into the field and the drop down values begin to filter. The user can continue to type their value or select from the shortening list of values.
In the client search editor, the list of values will filter out as the user types. This only applies to choice fields.
Please let us know if there are other places it would be nice to see the values filter as the user is typing in text.