The understanding of the word dhamma is a complicated and unresolved problem in the study of early Buddhism, and a protracted discussion is beyond this study. But I will at least comment on the meanings of dhamma in the Pārāyana Vagga.
In most places it simply means ‘teaching’ or ‘subject matter’. In one place it is an adjective meaning ‘nature’ in the sense of the main characteristic of a thing, and in another place it means “righteousness”. Variants on the idiom dittha-dhamma are found in four places, which Norman always translates as “in the world of phenomena”.  It seems that Norman relates this idiom to the expression ditthe va dhamme, for he translates the latter in exactly the same way. I am not sure of the exact meaning of this difficult expression, and although in this case Norman translates dhamma as ‘phenomena’, it is probably not relevant to the occurrence of dhamma in v. 1076. There are only seven more occurrences of dhamma in the Parayanavagga, but all of them have a direct bearing on the meaning of word in v. 1076; in virtually all of these occurrences, Norman translates dhamma as ‘phenomena’.
Three of these occurrences occur in the expression “gone to the far shores of all dhamma-s” (sabbadhammāna pāragu), an expression which describes the Buddha in Sn 992, 1105, 1112. Here, it is doubtful that the meaning of the word dhamma is ‘phenomena’ in general: if so, it would suggest that the Buddha had gone to the far shore of all phenomena, physical as well as mental phenomena, in which case he would be dead. In fact in two of these verses in which the expression “gone to the far shores of all dhamma-s” is found, it occurs among a group of adjectives that describe the mental state of the Buddha: in v. 1105 the Buddha is described as a meditator (jhāyiṃ) who is without corruption (anasavam) and without passion (virajam) and in v.1112 he is descibed as without desires (anejo), the one who has cut off doubt (chinnasamsayo). It makes better sense to suppose that the expression “gone to the far shores of all dhamma-s” in this context refers to the Buddha’s elevated mental state, i.e. that he is a meditator “gone to the far shore of all mental states/phenomena”. This must be true in the only other verse where the expression is found. In v. 992 the Buddha is said to ‘have vision into all dhamma-s’ (sabbadhammacakkhuma) and to ‘have attained the destruction of all dhamma-s’ (sabbadhammakkhayam patto). In the latter expression dhamma cannot refer to physical phenomena, for then the verse would be a eulogy of a dead person; the word dhamma throughout this verse must refer to mental phenomena. Moreover, the compound sabbadhammacakkhuma is similar to the phrase kusalo sabbadhammanam (v. 1039), which Norman translates as “skilful in all mental states”. They must have more or less the same meaning, i.e. that the Buddha is knowledgeable about the workings of the mind. The occurrences of dhamma in v. 992, which include the expression sabbadhammāna pāragu, must all refer to ‘mental phenomena’. This suggests that the word similarly means ‘mental phenomena’ in v. 1105 and v. 1112, as argued above for different reasons. The only other occurrence of dhamma is in the phrase upekhasatisamsuddham dhammatakkapurejavam (1107), which Norman translates as “purified by indifference and mindfulness, preceded by examination of mental states”. The word here could just as easily mean “doctrine”, i.e. “preceded by an examination of the doctrine”. It is even possible that the word has shades of both meanings; at least we can be quite sure that it does not refer to physical phenomena.

Alexander Wynne “The origin of Buddhist meditation”