Hello, everyone. 

I have a parent component, with a child component to simulate a multipicklist selection. I have to pass the list of selected values to the parent component, but it doesn't work. Does enyone know how to solve this? 

Child component:
<aura:attribute name="UFList" type="List" default="[]"/>
    <aura:attribute name="selectedUFList" type="List"  default="[]"/>
     
    <div class="slds-m-around_xx-small">
        <lightning:dualListbox aura:id="selectUF"
                               name="UF"
                               sourceLabel="Disponíveis"
                               selectedLabel="Selecionados"
                               options="{!v.UFList }"
                               value="{!v.selectedUFList}"
                               onchange="{!c.handleUFChange}"/>
        <lightning:button variant="brand" label="Salvar" onclick="{!c.getSelectedUF}" />
    </div>

Child controller:
getSelectedUF : function(component, event, helper){
        var selectedValues = component.get("v.selectedUFList");
        var componentEvent = component.getEvent("MultiPicklitsEvt");
            
            componentEvent.setParams({
                "UFVar" : component.get("v.selectedValues"),
            });
            
            componentEvent.fire();
        }


Event:
<aura:event type="COMPONENT"  >
    <aura:attribute name="UFVar" type="String"  />
</aura:event>

Parent component:
 <aura:handler name="MultiPicklitsEvt" event="c:MultiPicklitsEvt" action="{!c.handleMultiPicklitsEvt}"/>

Parent Controller:
handleMultiPicklitsEvt : function (component,event,helper) {
        
        var item = component.get("v.item");
        component.set("v.chosenUF", event.getParam("UFVar"));
        console.log(UFVar)
        
        item.UF__c = event.getParam("UFVar");
        log.console(chosenSP)
        
        component.set("v.item", item);     
    },