This looks strangely similar to the clamp on my Kuota Kharma (~2011). Firstly loosen the bolts and completely remove the saddle. Then you need to use the front screw to set the saddle angle, you might need to screw the front screw into /out of the post, as well as screw the clamping bracket up/down the screw. Once you've adjusted the saddle angle via the front screw, install the saddle and clamp down the rear screw. You will probably find clamping down the rear screw then screws up the saddle angle. So you need to go back and remove the saddle, adjust the front screw, install the saddle and then clamp down the rear screw. Now you might find that saddle is still not at the correct angle, in which case you need to remove the saddle, adjust the front screw, reinstall the saddle and clamp down the rear screw, and hope the saddle is at the correct angle. If it isn't then remove the saddle and repeat the process.

But the upside is, once I got it adjusted it has stayed there for the last 3 years.

Short answer is per poster ^^^, front screw adjusts saddle angle, rear screw clamps it down. Just wind the front screw down a little extra as clamping down the rear screw tends to tilt the saddle nose up.