Declension table of ?upāṃśvāyatana

Masculine	Singular	Dual	Plural
Nominative	upāṃśvāyatanaḥ	upāṃśvāyatanau	upāṃśvāyatanāḥ
Vocative	upāṃśvāyatana	upāṃśvāyatanau	upāṃśvāyatanāḥ
Accusative	upāṃśvāyatanam	upāṃśvāyatanau	upāṃśvāyatanān
Instrumental	upāṃśvāyatanena	upāṃśvāyatanābhyām	upāṃśvāyatanaiḥ upāṃśvāyatanebhiḥ
Dative	upāṃśvāyatanāya	upāṃśvāyatanābhyām	upāṃśvāyatanebhyaḥ
Ablative	upāṃśvāyatanāt	upāṃśvāyatanābhyām	upāṃśvāyatanebhyaḥ
Genitive	upāṃśvāyatanasya	upāṃśvāyatanayoḥ	upāṃśvāyatanānām
Locative	upāṃśvāyatane	upāṃśvāyatanayoḥ	upāṃśvāyataneṣu

Compound upāṃśvāyatana -

Adverb -upāṃśvāyatanam -upāṃśvāyatanāt