Events are always handled in the module that loaded the layout. You can pass the SplitPane to another module and load the layout there. You will not need to do anything special to work with the events and views from the other module.
Sub Process_Globals
Private fx As JFX
End Sub
Public Sub Show (parent As B4XView)
parent.RemoveAllViews
parent.LoadLayout("Layout1")
End Sub
Sub bt1LYT1_Click
Log("click")
End Sub
Main code:
B4X:
Sub ListMenu_SelectedIndexChanged(Index As Int)
Select Index
Case 0
Manage1.Show(pn)
Case 1
Manage2.Show(pn)
End Select
End Sub