Canon R5 has a
45.0MP Full frame (36 x 24 mm ) sized CMOS sensor and features Digic X processor. On the other hand, Leica SL2 has a
47.0MP Full frame (36 x 24 mm ) sized CMOS sensor and features Maestro III processor.
One other difference between these two cameras that is worth mentioning is that Leica SL2's sensor doesn't have an anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the R5 and SL2 sensor size comparison.
Canon R5 and Leica SL2 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture.