Filter on selected leaf node

Hi,

I have a table with 2 columns: source and target. Sample:

I created the column isLeaf to check for leaf nodes (True or False):

IsLeaf = 
    VAR CurrentNode = FullHierarchy[Target]
    RETURN CALCULATE (
        COUNTROWS ( FullHierarchy ),
        ALL ( FullHierarchy ),
        FullHierarchy[Source] = CurrentNode
    ) = 0

Also, the path is calculated using the PATH() function.

Next, I created the disconnected table Leafs containing only the leaf nodes:

Leafs = 
    SELECTCOLUMNS(
        FILTER(FullHierarchy, FullHierarchy[IsLeaf]),
        "LeafNode", FullHierarchy[Target]
    )

This is the result: 2 disconnected tables.

My goal is to have 2 visuals: a slicer based on Leafs and a table based on FullHierarchy. Selecting a leaf shows only the items that are directly or indirectly connected to it (i.e. part of it's path).

The statement to do so would be something like:

PATHCONTAINS(
    LOOKUPVALUE(FullHierarchy[Path],
                FullHierarchy[Target]
                [Selected Node]),
    FullHierarchy[Target])

The statement above would lookup the path for the selected leaf node, and then check if the node in the table was part of it, to decide whether or not to show it.

I've tried countless of variations, but have unable to implement this. Any ideas, suggestions, etc would be greatly appreciated! Thank you!

Sample pbix file is available here.