How to identify the anode and cathode in a concentration cell?
Let's restate the problem: we have two hydrogen half-cells with other stuff in them. Hydrogen electrodes will have voltages related to their pH, because that is the definition of a hydrogen electrode. Then it goes haywire: does one half-cell contain BaCl2 and the other contain Be(OH)2 at 0.5 M - certainly not BaCl and BeOH. In fact, Be(OH)2 is amphoteric and soluble at only 2 ppm, so even estimating the pH of that cell would be a blind guess; you could guess the BaCl2 solution to be about 7.0, but might be a tiny bit different.

I suspect the question is not one that has actually been created and measured, but is rather a made-up question with no dependence on reality, to ask how to visualize  two hydrogen electrodes in pH 7 (the BaCl2 solution) and pH 13.69 (pH of 0.5 M OH), which could not occur because of the low solubility and amphotericity of Be(OH)2. So the whole cell could be written:

Pt(H2,1 atm)|H+(aq,10e-7 M)||(H+(aq,10e-13.69 M)|Pt(H2,1 atm)

or, just consider both half cells to be at pH 7 and there's no overall cell voltage (my preference).