Complex sentence: Brahma loka, Vaikunta loka, Satya loka and Shiva loka are seen as the same and form together the highest loka (dimension) of the 14 lokas.
Split into simpler sentences: Brahma loka, Vaikunta loka, Satya loka and Shiva loka are all the same (dimension). These together form the highest loka (dimension) of the 14 lokas.