Complex sentence: Garbhodakaśāyī Viṣṇu is an expansion of Mahā Viṣṇu (expansion of Saṃkarṣaṇa of second caturvyūha, that, which expands from Nārāyaṇa in Vaikuṇṭhaloka), and also the later is realized as the expansion of Pradyumna.
Split into simpler sentences: Garbhodakaśāyī Viṣṇu is an expansion of Mahā Viṣṇu (expansion of Saṃkarṣaṇa of second caturvyūha, and which, expands from Nārāyaṇa in Vaikuṇṭhaloka). Additionally, the later is realized as the expansion of Pradyumna.