From my memory of Hlist, I think you can get the closest element to a x-y mouse event. Here is a an old tip I found:

========
> atm when I right click on an entry in my hlist it doesnt select the
> entry currently under the mouse pointer (ie explorer like behaviour)
+.
> Can some1 give me a few pointers.
>
I've had the same problem and this is my solution -
when user press <Button-3> we send <Button-1> with same coords.

$tree->bind("<Button-3>" => [\&menu_popup, Ev('x'), Ev('y')]);

sub menu_popup {
    my ($wg,$x,$y) = @_;
    $wg->eventGenerate('<Button-1>', -x => $x , -y => $y );
    if (my $sel=$wg->info("selection")) {
        $menu->Popup(-popover => "cursor",
                 -popanchor => 'nw')
    }
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