This complex fraction presents the interesting problem of having a cancelled denominator in the numerator of the larger overall (complex) fraction. Although I have presented the solution, I encourage you to read my explanation for understanding of the application of the rules, so that you can apply the same logic to further problems.
Since we are required to braille a fraction containing cancellations spatially (NC Sec.60), you will have a spatially-arranged fraction in the numerator of this spatially-arranged complex fraction.
In your example, the denominator has no cancelled items and so is brailled linearly within the overall arrangement. The numerator requires a spatial presentation of the simple fraction. The first factor in the numerator, as well as the parentheses which enclose the second factor, are brailled on the main line of the spatially-arranged simple fraction--that is, on the line which contains the fraction line. Items are centered over/under their respective fraction lines.
Take a look at example (3) on page 79 of the Nemeth code for a different application of the same general idea. Although the codebook example illustrates a hypercomplex fraction, it demonstrates spatially-arranged numerators and denominators within a larger structure.