I can select all objects in current layer with the following
but, how do I loop through all layers and add their shapes to Selection?
Depending on the content you are trying to access, you might use ActivePage.Shapes.FindShapes().
FindShapes can be recursive (dig into groups) or non-recursive, and you can use a CQL query to exclude specific content (e.g., guidelines, shapes on specific layers, shapes on locked layers, etc.).
So something such as this:
Dim sr As ShapeRange
Set sr = ActivePage.Shapes.FindShapes(, , False, "@type != 'guide' and @com.layer.isguideslayer = 'False' and @com.layer.isdesktoplayer = 'False'")
That works also; thanks kindly!