The following is dyno graph of a 1098/848 Ohlins TTX rear damper. The adjusters for both compression, and rebound control a bleed orifice that directly affects the low speed operation of the damper.
The result of adjusting one or the other is carried on through out the entire working range of the damper.
The adjustment range is quite impressive. As the adjuster get closer to being full stiff (closed) the individual clicks get quite powerful.
It is important to note that your spring package should be optimized for your weight and riding style before you attempt to adjust the damper. This will ensure that the damper/fork and spring package work together to deliver the desired performance.