I don't have a source for the specific issue of areas of Torah study intersecting, but you may find this helpful, on the topic of signs or "hints" Hashem sends us:
"You should reflect on the different situations and occurrences that God sends your way day by day. Each day has its own thoughts, words and deeds. They are all completely unique to that day. God "contracts" His infinite, endless Godliness in such a way that Godliness is present even in the innermost point of the finite material world in which man finds himself. Thus God sends to each individual the thoughts, words and deeds appropriate for the day, the person and the place. Within them are hints intended to draw the person closer to God's service.
This is why you should pay attention to what happens to you and consider what it may signify. Think about the thoughts, words and deeds that God sends you each day in order to understand His hints to you to draw closer to Him at every moment. This applies to everyone, no matter who and in what circumstances .
But be cautious when thinking about these things: you must stay within certain limits and not delve to excess, because otherwise it is possible to stray beyond the bounds of holiness. Flying off into speculation can be dangerous. Stay within the limits of human understanding and steadily expand your horizons without trying to step beyond your level, because 'you may not investigate that which is too wondrous for you'(Chagigah 13a)."
Likutey Moharan I, 54