I don't claim to know all of R. Joseph B. Soloveitchik's philosophical influences. All I can say is that I noticed some commonalities between R. Soloveitchik's thought in his book The Emergence of Ethical Man and that of Martin Heidegger. Whether R. Soloveitchik acquired them in Berlin in the 1920s, from Heidegger's writing(s) or from a secondary source such as Martin Buber's writings, I can't say. But the similarities are too strong to suggest that this is just a coincidence.
1. Field of Being
Existence itself, according to Heidegger, means to stand outside oneself, to be beyond oneself. My Being is not something that takes place inside my skin (or inside immaterial substance inside that skin); my Being, rather, is spread over a field or region which is the world of its care and concern. Heidegger’s theory of man (and of Being) might be called the Field Theory of Man (or the Field Theory of Being) in analogy with Einstein's Field Theory of Matter, provided we take this purely as an analogy...Entirely the same? No. But R. Soloveitchik was reacting to concepts that Heidegger first enunciated.
(William Barrett, Irrational Man, p. 194)
In the mineral world, it is impossible to speak of an object and its environment or outside; the object is a part of its environment... But we do speak of a structured organism-environment field, and although there is interaction between a living structure and its outside world, we still consider the organism to be a bounded entity, rooted in inner existence. There is a reciprocity but also a polarity of within and without...
Man and animal were granted the capacity for movement, making them more "self-contained" than the plant, which is rooted in Mother Earth... We cannot speak of them as integrated with a fixed environment. Nevertheless, even they are enmeshed within the outside world and flow into the non-self. Thus, certain viewpoints will tend to bring man closer to his environment on the model of the plant's unity with the outside world; other viewpoints, on the contrary, will strive to grant man more freedom and self-sufficiency.
 The field theory in physics, which dissolved allegedly concrete encapsulated objects into abstract fields of force, accomplished the feat of removing all boundary lines between objects and their environment.
(R. Soloveitchik, The Emergence of Ethical Man, pp. 14, 16-17)
2. Flow of Time
These three tenses of time--future, past, and present--Heidegger calls ekstasies, in the literal sense of the Greek ek-stasis, a standing outside and beyond oneself. Philosophers before Heidegger had constructed time as a series of "nows"--present moments--following each other like points upon a line... But in order to construct time as a sequence of "nows" we have to be able, Heidegger says, to understand what "now" means; and to do this we have to understand it as the moment dividing the past and future--that is, we have to understand past and future together in order to understand the present. Hence, every attempt to interpret time as a sequence of present moments, sliding away into the past, presupposes that man already stands beyond himself in one of the three ek-stases of time. His existence is thus a field spread out over time as it is over space...Again, not exactly the same. Especially since Heidegger emphasized the future while R. Soloveitchik gave both the past and future equal emphasis. Nevertheless, the similarities are clearly no coincidence.
(Barrett, p. 203)
History, as a human event, unfolds itself in time... Yet there is an experience of closeness in historical time. Instead of being a straight line extending in two opposite directions, time presents itself as a three-dimensional magnitude--past, present and future--that envelops the historical consciousness, that explores not only the traces of a bygone past retained in memory and a non-existent future anticipated in fantasy, but a living past and future which are projected against the backdrop of the present. The historical texture is woven of past and future; it is a focus in which the bygone and the expected converge. To live historically means to live through all the phases of history, both past and future...
(R. Soloveitchik, p. 164; cf. The Lonely Man of Faith, end of part VI; Festival of Freedom, p. 175ff.)