How to fix multiple seperate buffers? (HL2 Update)

After a lot of hassle, the depth buffer for Half-Life 2: Update works for me, however not in the way I want it. I need to preserve the buffer from being cleared, and I'm presented with 3 different buffers to use - One being basically nothing, the other two are separated views of the game world and the skybox. I understand that Source games like to separate the viewing of the skybox because of the laughably small map size it has, and I saw in a bunch of other threads of screenshots with the physical world and the skybox in the same buffer, so how can I achieve this?

I'm having the same issue. I need the depth filter to work correctly in order to use quint_rt's ray tracing effects.
I have no idea on how to set up this anymore. Every time it seems to be working OK, it stops working, reset's the filter, and after installing MMOD, everything went to s**t...