"لا أُحِبّ اَلْنَّوْم بَعْد اَلْظُّهْر."
Translation:I do not like sleeping in the afternoon.
بعد الظهر is more general than العصر - in the sense that it includes all the time after the sun's mid=point in the sky (الزوال) until the time before dusk (الغسق).
On a side note, the speaker might mean (not wanting to sleep at the time just after the noon time). Not all the times after noon are العصر.