Here is a note of commentary by Robert Eno on this verse:
"“Roots and branches” points towards causes and consequences; “ends and beginnings” points towards continuity in the flow of apparently sequential events. Effective action in the midst of life requires the identification of priorities
and a vision of receding consequences
- emphasis added)
He seems to be hitting at two types of priority: chronological and logical (for lack of a better term).
Chronological priority would mean knowing what should come first in order: "A journey of a thousand miles begins with a single step...", right? We shouldn't strive too hard or get ahead of ourselves, but we should focus on those first steps. Or simply the next step, according to wherever we might be at a given moment. I get a lot of this from his comment on "consequences" as well as the natural reading of the text ("beginning" and "end," etc.).
Logical priority--maybe essential priority is a better way of describing it?--would mean making sure we know that which is first, not in order or time, but in importance. So, when you look at it this way, branches are secondary. Not just because they come after the roots, but because the roots are more essential to the process as a whole. The roots can survive branches getting blown off in a storm, but the branches cannot survive the roots being dug up and removed. I get this from looking at his comments on identifying priorities.
If this is a recipe for nearness to the Dao, then perhaps we come near to the Dao when we realize what is (reverse order) most essential and what our next step should be.