Question : load a subtree into an XDocument

I load an XML document in VB using Dim doc As XDocument = XDocument.Load(XmlFilePath) , all is fine.
Dim doc As XDocument = XDocument.Load(XmlFilePath)


what i want to do is :

Dim docFrameElements As XDocument = .. the tree of nodes under "FrameElements"
Dim docInteractions As XDocument = .. the tree of nodes under "Interactions"

Can you offer me vb sytnaxt to do that sort of thing please.
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