In the latest versions of AEM when dealing with multifield, you can set composite="{Boolean}false" or composite="{Boolean}true."
composite="{Boolean}false" = stores the multilist items into a String[] in side of the resource's properties.
composite="{Boolean}true" = stores the multilist items individual nodes.
<damAssetPaths
jcr:primaryType="nt:unstructured"
sling:resourceType="granite/ui/components/coral/foundation/form/multifield"
composite="{Boolean}false"
fieldDescription="Content Fragment Paths"
fieldLabel="Content Fragment Paths">
<field
jcr:primaryType="nt:unstructured"
sling:resourceType="granite/ui/components/coral/foundation/container"
name="./damAssetPaths"
required="true"
rootPath="/content/dam/advancedbionics">
<items jcr:primaryType="nt:unstructured">
<damAssetPaths
jcr:primaryType="nt:unstructured"
sling:resourceType="granite/ui/components/coral/foundation/form/pathbrowser"
name="./damAssetPaths"
rootPath="/content/dam/advancedbionics"/>
</items>
</field>
</damAssetPaths>