Hadith: The dwellers of Paradise will look at the dwellers of the lofty chambers above them in the same way that you look at a shining star far away on the horizon, in the East or in the West, due to their superiority over one another

عَنْ أَبِي سَعِيدٍ الخُدْرِيِّ رَضِيَ اللَّهُ عَنْهُ عَنِ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ، قَالَ:

«إِنَّ أَهْلَ الجَنَّةِ يَتَرَاءَوْنَ أَهْلَ الغُرَفِ مِنْ فَوْقِهِمْ، كَمَا يَتَرَاءَوْنَ الكَوْكَبَ الدُّرِّيَّ الغَابِرَ فِي الأُفُقِ، مِنَ المَشْرِقِ أَوِ المَغْرِبِ، لِتَفَاضُلِ مَا بَيْنَهُمْ» قَالُوا: يَا رَسُولَ اللَّهِ تِلْكَ مَنَازِلُ الأَنْبِيَاءِ لاَ يَبْلُغُهَا غَيْرُهُمْ، قَالَ: «بَلَى وَالَّذِي نَفْسِي بِيَدِهِ، رِجَالٌ آمَنُوا بِاللَّهِ وَصَدَّقُوا المُرْسَلِينَ».
[صحيح] - [متفق عليه]

Abu Sa‘īd (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "'The dwellers of Paradise will look at the dwellers of the lofty chambers above them in the same way that you look at a shining star far away on the horizon, in the East or in the West, due to their superiority over one another.' The Companions said: 'O Messenger of Allah, are these lofty chambers for the prophets and nobody else can reach them?' He replied: 'No! By Allah in whose Hand my soul is, these are for the men who believed in Allah and believed the Messengers.’"
Sahih/Authentic. - [Al-Bukhari and Muslim]

Explanation

The dwellers of Paradise will be in different levels according to their level of virtue, such that those in the high levels will be seen by those below them just as the stars are seen in the sky