How to link two listboxes to select/deselect and fire command

See more:

C#

VB

WPF

MVVM

Hi,
My Scenario:

Two ListBoxes - Listbox_01 and Listbox_02.
Listbox_01 ItemsSource is bind to a ObservableCollection in a ViewModel, SelectionMode set to Multiple, with attached property to limit the selection to 2 items. SelectedItems (dependency property) is bind to a property (IList) on ViewModel
Listbox_02 ItemsSource is bind to a property (IList) on a ViewModel (SelectedItems from Listbox_01). SelectionMode set to Single.
When I select items from Listbox_01 all should appear in a Listbox_02. This works for me. The question is, How can I link these two Listboxes to select and deselect items between them.
If I select two items from Listbox_01 they will be visible in Listbox_02. Then, when I select item from Listbox_02 it should get selected item (columns or content), fire command (RelayCommand), deselect that item on Listbox_01 and disappear from Listbox_02.

The problem here is that, when I click on Listbox_02 item there is always selection on Listbox_01 and the item that disappear from Listbox_02 is not correct (when I have two items, I click on the item_02 to close it, item_01 disappears)

Listbox_01 is only for selecting items. Listbox_02 is to execute command.

My code:
Listbox_01

<listv:ListViewSelectedItemBehavior SelectionMode="Multiple"
                                    ItemsSource="{Binding EmployeeViewM.MainActivity}"
                                    SelectedItemsList="{Binding EmployeeViewM.SelectedAll, Mode=OneWayToSource}"
                                    Background="{x:Null}"
                                    BorderBrush="{x:Null}"
                                    IsSynchronizedWithCurrentItem="False" >

Listbox_02

<listv:ListViewSelectedItemBehavior SelectionMode="Single"
                                    HorizontalAlignment="Left"
                                    ItemsSource="{Binding EmployeeViewM.SelectedAll}"
                                    SelectedItemsList="{Binding EmployeeViewM.SelectedAll, Mode=TwoWay}"
                                    Background="{x:Null}"
                                    BorderBrush="{x:Null}"
                                    IsSynchronizedWithCurrentItem="False">

SelectedAll IList

Public Property SelectedAll() As IList
    Get
        Return _selectedAll
    End Get
    Set(value As IList)
        _selectedAll = value
        RaisePropertyChanged("SelectedAll")
    End Set
End Property

What I have tried:

SelectedIndex, SelectedItem, DataGrid instead of ListBox,