Hello,
I assume that you’ve exported your textures from Substance Painter with the default UE4 packed settings. 
So here’s what you need to do from there:
- Directly import each texture inside Unreal.
- For both Occlusion Metallic Roughness maps, either uncheck the sRGB checker or change the compression profile to **Masks (No sRGB) ** (see screenshot 1)
According to this, “in compression profiles that support it, sRGB can be enabled/disabled via a checkbox under the Texture subheading in the Properties Editor. The Masks profile is functionally the same as the Default profile with the sRGB setting manually unchecked.” - Make sure each normal map is imported as normal map
- Create 2 materials and import each set of textures (the leg & the table top).
- In each material, plug each texture to specific nodes, exactly like I did in the screenshot 2.
Just a bit more info, each RGB channel used in the occlusion/ metallic/ roughness map (Red = Ambiant Occlusion, Blue = Metallic & Green = Roughness) is customizable inside the Substance export settings (that’s why my screenshot works only if you didn’t changed the default settings).
Enjoy
Screenshot 1
Screenshot 2
