I created an array of SelectItem objects and bound it to the ace:autoCompleteEntry component like this:

            <ace:autoCompleteEntry value="#{navigationModel.searchValue}"
                                   valueChangeListener="#{navigationController.navigate}"
                                   placeholder="Search"
                                   filterMatchMode="contains"
                                   width="180">
                <f:selectItems value="#{navigationModel.currentComponentGroup.searchSelectItems}"/>
            </ace:autoCompleteEntry>

The event in the ValueChangeListener is returning the selected label as the new value, instead of the value used in creating the SelectItem object.

The showcase uses a SelectItem constructor with a single parameter, the label that is used for label and value. We need it to work with the SelectItem constructors that also pass in a separate value.