In plain words
Others, worshipping through jñāna-yajña, adore Me: some as one, some as distinct, and some in many ways, as the One who faces in every direction.
Word for word
And others too, worshipping by jñāna-yajña, worship Me as one, as distinct, in many ways, [Me] whose face is everywhere.
The commentators
Bhagavadgītābhāṣyam
ते केन केन प्रकारेण उपासते इत्युच्यते —
ज्ञानयज्ञेन ज्ञानमेव भगवद्विषयं यज्ञः तेन ज्ञानयज्ञेन, यजन्तः पूजयन्तः माम् ईश्वरं च अपि अन्ये अन्याम् उपासनां परित्यज्य उपासते । तच्च ज्ञानम् — एकत्वेन ‘एकमेव परं ब्रह्म’ इति परमार्थदर्शनेन यजन्तः उपासते । केचिच्च पृथक्त्वेन ‘आदित्यचन्द्रादिभेदेन स एव भगवान् विष्णुः अवस्थितः’ इति उपासते । केचित् ‘बहुधा अवस्थितः स एव भगवान् सर्वतोमुखः विश्वरूपः’ इति तं विश्वरूपं सर्वतोमुखं बहुधा बहुप्रकारेण उपासते ॥ १५ ॥
In plain words
In which ways, one by one, do they worship? To that, the answer is given:
There are those who approach Me through the sacrifice that is knowledge itself — knowledge with Me, the Lord, as its very object; that is their offering, and through it they honor Me. And there are others who set that path aside and worship in a different way altogether. That knowledge, in fact, takes three shapes. Some see through the lens of oneness: 'There is only the one, supreme Brahman' — and worship out of that vision of ultimate reality alone. Some see through the lens of difference: 'In the sun, in the moon, in each distinct form, that very Lord Viṣṇu is present' — and worship him there, in each. And some see him everywhere at once: 'Present in countless ways, that very Lord, facing every direction, is the form of the whole universe' — and it is that universal, all-facing form they worship, honoring him in however many ways they can find.
Close to the Sanskrit
By what and what manner do they worship — thus it is said:
By the sacrifice of knowledge — [that is,] knowledge itself, having the Blessed Lord as its object, is the 'sacrifice'; by that sacrifice of knowledge — worshipping, [that is,] honoring Me, the Lord, others too, setting aside another mode of worship, worship [in yet another way]. And that knowledge [is of three kinds] — by way of oneness: 'The one, supreme Brahman alone [exists]' — through this vision of ultimate reality, worshipping, they venerate [Me]. And some, by way of difference: 'Through the distinction of the sun, the moon, and so on, that very Blessed Viṣṇu is situated [in each]' — thus they worship. Some [worship thus]: 'Situated in many ways, that very Blessed [Lord], facing in all directions, is of universal form' — thus, him, of universal form, facing in all directions, in many ways, [that is,] in many modes, they worship.