Thank you for your answer. I think you can implement it using two blocks in series (and not in parallel like the one formerly attached). The first block simply omits the signal parts with power level below p1, whereas the second block omits the parts above p2. The second block consists of two parallel parts, with the upper part being merely the input signal to the second block and the lower part omitting the parts below p2. At the output of the second block, the two signals from the upper and lower parts are subtracted and the intended signal would be obtained.
Regards