After receiving and answer to this question, I am stuck with another problem.
For context, my end goal is to assess windward/lee side of a forested edges (line segments) in respect to a dominant wind direction. Following the answer in the linked question, I have created an offset point on the inside edge of each line segment. I now am trying to evaluate these line segments based on the azimuth of the offset (segment midpoint to offset midpoint).
How can I reference the offset point in an expression in a field calculation on the original line segment?
How do I reference offset_point if it is in another layer?
If it is another feature in the same layer?
psuedocode: offset_azimuth = degrees(azimuth(segment_midpoint, offset_point)) if(offset_azimuth = (windDir +/- 45), "Lee", "Windward")